Homage to Catalonia: Claudia Roden has spent four decades taking our tastebuds on a grand tour

In the course of her culinary travels among the chefs, connoisseurs and gourmets of Spain, Claudia Roden met a grand academic lady of Madrid whose husband came from the Castilian aristocracy. As you might expect from a food writer who, over four decades, has opened our eyes and accustomed our tastebuds to the pleasures of the Middle Eastern, north African and Jewish tables, Roden's research often carries the Islamic and Jewish heritage of Spanish food out of the shadows and into the spotlight. Many local foodies now join her in celebrating the glorious mish-mash of their country's edible heritage. But not the posh professor. "I certainly encountered people who were in denial," Roden recalls. "She epitomised a few who felt like that."

At dinner in her apartment, the academic insisted: "Claudia, you must understand that we come from Roman and Visigothic stock." Yet, in order to prove her multicultural goodwill, she then went off to change into a belly-dancing costume. And she proudly showed Roden the recipe for houmous stuck to the fridge door: "It meant that she wasn't a racist!"

Ah, houmous. Many students of British food and its recent evolution credit the ubiquity of the chickpea-tahini-lemon-garlic grit to Roden herself. First published in 1968, her debut – A Book of Middle Eastern Food – still arouses intellect and belly with undiminished power. During the first two postwar decades, Elizabeth David and her disciples had acclimatised British palates to the Mediterranean diet in its north-coast, Catholic and Orthodox aspects. Roden scoured the whole basin and its hinterland, restoring Muslim and Jewish cookery in the region to their places in the sun. As Madhur Jaffrey soon would do with the food of India, she made formerly remote cuisines approachable. By dint of profound understanding, gentle instruction about ingredients and techniques, and sheer practicality, she turned the "exotic" dish into an everyday staple.

I speak from experience. It isn't often you interview an author who has – without any hyperbole – helped to keep you alive. As a student with a modest grant (yes, those were the days), I once rashly decided to shun the shared house in favour of splendid isolation in an expensive flatlet with a tiny kitchenette attached. It had been carved out of an accountant's ugly modern detached home. He and his wife were, I soon discovered, at war over his secretary-cum-girlfriend. So as the shrieks from ever-fiercer rows pierced the thin partitions, I stood in the micro-kitchen with a stained and ragged Penguin Book of Middle Eastern Food and cooked my way through Claudia's cheaper veggie options. I ate like a pasha, on next to nothing. My Proustian madeleine from that time takes the form of lentil and vegetable stew, its humble pulse-and-root ground bass transfigured by a lemony cadenza. I made that dish in life-sustaining vats.

Today, Claudia Roden is building up my strength again. We begin to talk, and eat, amid the April birdsong in the garden of her house in Hampstead Garden Suburb: an Edwardian dream of such biscuit-box deep-English sweetness that it would be less surprising to find her in some Moroccan riad or Turkish yali. Before a moody afternoon drives us inside, I sample a simply immaculate walnut cake from her lavish, eclectic but never pretentious new book, The Food of Spain. In the kitchen, she follows up with an ice cream made with raisins and unctuous Pedro Ximenez sherry. If I'd turned up at lunchtime, I would have scoffed a version of the ever-changing salmorejo, a hearty Andalucian soup – the more robust brother to gazpacho – that "I keep on doing again".

All Roden's books draw on dialogues with cooks, amateur as much as professional, and their own histories of taste. "Food is very convivial and personal," she says. "There are all kinds of sayings in the Muslim world: 'If you have eaten together, you can't betray each other'. To me, it does open all the doors." When she went recipe-hunting with a foodie party to Hezbollah-dominated districts in Lebanon, "Everybody knew I was Jewish. But I was more popular than the others."

As the books take shape, story by mouth-watering story, her unaffected warmth and free-range curiosity ease a passage not just into the mysteries of the local menu but into the complex pasts – of individuals, families and whole communities – that lie behind them. For her, food and its pursuit "certainly brings empathy. When you're invited into the kitchen, it's a completely different feeling from when you're sitting in the living room. In the kitchen, everybody pours out their anger, their stories. People do tell strangers things they wouldn't tell somebody they know: there we are, cooking, and a lot of things come out. Research becomes an encounter with people and their lives."

The Food of Spain boasts a cast of recipe-sharing characters as varied as its recipes They range from the gourmet Count of Ybarra in Cadiz to the octogenarian nun Sister Angelita – an expert in croquetas – from Seville; and from the artist Jose Luis Alexanco, who via the austere gachas porridge preserves the memory of the "tough years" after the civil war, to Pepa Aymami, a blonde Barcelona "livewire" who directs the Catalan Culinary Institute.

The memories, and emotions, of those who cook and eat have always added an extra depth of flavour to Roden's adventures in food. Indeed, these began with a mission to recover the taste of a lost homeland. She was born in pre-war Cairo, part of a firmly rooted Egyptian Jewish middle class. Such f merchant communities flourished all over the Ottoman empire. Among the polyglot family's languages was Ladino, the Judaeo-Spanish brought across the Med after Christian Spain's slow, suicidal suppression and expulsion of Moors and Jews in the century after 1492.

Most of her ancestors had come from Syria. A great-grandfather was Chief Rabbi of Aleppo. As a child in the gracious suburb of Zamalek, an island in the Nile, she belonged to a people and a culture that felt rock-solid. Yet it crumbled within a few short years: "Somehow a whole cosmopolitan world that we were part of disappeared." Tensions in the wake of the creation of Israel, and then the tumult of Nasser's nationalist revolution in Egypt, shattered the bedrock of Jewish Cairo.

Most of the community left Egypt, forced out by high-level politics rather than street-level prejudice: "People were desperately sad to see us go." Latervisits revived an affection for her native land – "I just felt totally happy there, with everybody." Now, however, she worries about the power of the Muslim Brotherhood in the wake of last year's revolution.

Roden finished her schooling in Paris and then studied art at St Martins College in London. In exile, living in Golders Green, her parents and their Cairo friends clung to the flavours of home. Family recipes almost acquired the status of scripture. "People were desperately afraid of losing them." So she began seeking out and collecting hand-written notes from homesick expatriates. Thus the tastes of old Cairo and Casablanca, of Damascus and Salonica, found their way into A Book of Middle Eastern Food. It transformed the nostalgia of exiles into the fashions of the supermarket shelf and the suburban dinner party. Meanwhile Roden had married, raised three children, then divorced. Food moved from hobby to livelihood. She gave cookery classes, and then the enduring success of her debut led to a line of works whose seamless blend of technique and context fed the imagination even as they satisfied the stomach: The Food of Italy; Arabesque; Tamarind & Saffron; above all, her monumental Book of Jewish Food.

With its many echoes of the Jewish and Muslim Middle East, the Spanish kitchen – which "brought together dishes from all my worlds" – felt to her like a homecoming. "I knew it was going to a be a very exciting place," she says, "but I never expected it to be that exciting – and moving. It meant a lot, because of the culinary side but also the whole history and background. I kept being amazed. The smells brought back my childhood. I could always see very well where things came from. And when I did research, it always fitted in like a puzzle."

Even the national prestige of the pig and all its by-products, still 'king' of the kitchen across Spain, turns out to have an intimate connection to the long-buried multicultural past. Conversos (former Jews) and Moriscos (former Muslims) naturally flaunted their pork-eating as evidence of Christian faith. But, Roden believes, even those who secretly adhered to the religion of their forefathers would keep bits of ham handy for the pot should the Inquisition come to call. A public passion for the tasty hog might deflect all manner of suspicion. She quotes a poem by the 16th-century Sevillian Baltazar de Alcazar: "Three things hold my heart a prisoner of love – fair Inés, ham and aubergines with cheese". Our jamón-worshipping Baltazar was, it appears, of Jewish descent.

Suffused by the flavours of the past, The Food of Spain nonetheless carries a jacket endorsement from Ferran Adrià of El Bulli. Now, Roden – as always – stuffs her pages with delicious and fuss-free recipes that make no outlandish demands on the cook: "I always feel an obligation to people who are going to use the book. I know how hard they work." She cherishes the rustic as much as the refined. But does her manifest love of tradition set her at odds with the cult of gadget-driven gastronomy, as modish in Spain as anywhere else?

Certainly, when she visited cookery schools, she found that young chefs "want to be like Ferran: they all want technology and to use all these machines to freeze-dry, to explode, to make foams." But, with the backing of Adrià himself, a counter-current has begun to flow. Even the most star-studded young restaurateurs now yearn for a return to family roots. There's "not a backlash, but a campaign" to restore traditional Catalan cuisine in particular.

Before I leave, I want to know which chefs and restaurants today earn her approval. Among Spanish-flavoured outlets in London, she endorses Fino and Moro, whose Sam and Sam Clark "have such good taste". From other traditions, she has warm praise for Giorgio Locatelli, Raymond Blanc and Fergus Henderson: "I really adore Fergus: his cooking, his spirit, his style." Yottam Ottolenghi, whose approach some may see as a chip off the Roden block, she hails as "an artist and a master." But perhaps we should redact the names out of her report on another chef's catastrophic foray into Middle Eastern nouvelle cuisine: Moroccan pigeon pastilla with Indian chutney inside; tabbouleh with mussels. "It was awful. I just thought, I don't want to eat that."

"In my view," she explains, "people can do what they like – as long as it tastes good. But if we're going to lose what was part of an old culture that slowly developed, to change just because you've got to find something new – that isn't a good idea. I think a lot of people are just messing about." I can't imagine a better antidote to gastronomic "messing about" than Claudia Roden. Turn to page 289 of The Food of Spain and you'll find a recipe for migas con tocino: fried breadcrumbs with bacon, hot pepper and loads of garlic. It's evidence, as the book tells us, of a new respect for the dishes of the very poor that forms part of Spain's gradual embrace of its discordant past. As so often in her work, this is food that smacks of history, with all its divisions and its heartaches. And, as I found over my student stewpot as a marriage melted down through the walls, it can offer never-failing comfort "for the stomach and for the soul".

'The Food of Spain: a celebration' by Claudia Roden is published by Michael Joseph (£25)

Orange flan

Serves 8

I love this refreshing, slightly tangy, creamy custard. It is just what you need to end a rich meal. You must use freshly squeezed orange or clementine juice and it is best if you squeeze the juice yourself.

600ml fresh orange or clementine juice
125g sugar
10 large egg yolks
2 large eggs

Heat the citrus juice with the sugar in a saucepan over a low heat and stir to dissolve the sugar. Beat the egg yolks and the whole eggs lightly with a fork in a large bowl. Then gradually beat in the citrus juice. Ladle the mixture into eight 175ml ramekins. Place them in a large shallow pan, pour in boiling water to come halfway up the sides of the ramekins (this water bath is called a bain-marie) and bake in an oven preheated to 150C/gas mark 2 for 30 minutes or until the custard sets. It needs to be cooked at a low temperature to get a perfectly smooth texture without bubbles. Take the ramekins out of the pan and let cool, then chill in the refrigerator, covered with clingfilm, until ready to serve.

Vegetables with a tomato and hard-boiled egg vinaigrette Serves 4-6 There are many versions of Spanish vinaigrette.

Vinagreta adds glamour and flavour to a simple dish of boiled vegetables and makes it light and refreshing, as well as an elegant start to a meal.

The vegetables can be served hot or at room temperature and they can be prepared in advance.

All kinds of vegetables may be used for this recipe; you can substitute or add others, such as carrots, runner beans, green beans and cauliflower. The main thing is to make sure that you give each vegetable the right cooking time. Leeks have to be very well cooked and soft while asparagus are best a little crunchy.

4 leeks
About 500g new or waxy potatoes
250g asparagus
3 fresh baby artichoke hearts or frozen and defrosted artichoke hearts
Salt

For the vinagreta

7tbsp extra virgin olive oil
2tbsp white wine
Vinegar or juice of half a lemon
Salt and pepper
2tbsp finely chopped flatleaf parsley
2 firm tomatoes, chopped
1 hard-boiled egg, peeled, chopped

Trim and wash the leeks, cut off the green ends and cut each of them into three pieces. Peel the potatoes and cut them in half. Trim the hard ends of the asparagus. Cut the artichoke hearts or bottoms in half. Put a large pan of salted water on to boil and throw in the leeks and potatoes. Simmer for 10 minutes, then add the artichokes. Cook for 5 minutes, then add the asparagus and cook for 5 to 10 minutes more until all the vegetables are done. Drain well and arrange them in a wide serving dish. While the vegetables are still warm make the vinagreta. Beat the oil and vinegar or lemon juice with some salt and pepper in a bowl. Stir in the parsley, chopped tomatoes and hard-boiled egg and pour over the vegetables, turning them so that they absorb the dressing well.

Seafood paella

Serves 4

1 large onion, finely chopped
5tbsp olive oil
2 garlic cloves, peeled and crushed
2 tomatoes, peeled and chopped
tsp each sugar and salt
1tsp sweet paprika
A good pinch of saffron threads
4 small squid, cleaned, the bodies sliced and tentacles left whole
400g Spanish risotto rice
750ml fish or chicken stock, plus more if needed
250ml dry white wine
12 raw king prawns in their shells
16 mussels or clams, cleaned

Fry the onion in the oil in a 40cm paella pan over a low heat until soft, stirring often. Stir in the garlic, and before it begins to colour add the tomatoes. Add the sugar, salt, paprika and saffron, stir well; cook over a medium heat until the tomatoes are reduced to a jammy sauce and the oil sizzles. Add the squid; cook, stirring for a minute or so, then add the rice and stir until all the grains are coated.

Bring the stock and wine to the boil and pour on the rice, then add salt. Stir well and make sure the rice is evenly distributed in the pan, then do not stir again. Cook the rice over a low heat for 18 to 20 minutes, moving the paella around on the hob so that it cooks evenly. Lay the prawns on top of the rice after 10 minutes and turn them over when they turn pink on the bottom side.

Add a little more hot stock towards the end if the rice seems too dry and you hear crackly frying noises from the bottom of the pan before it is done, and cover the pan with a large piece of foil. Steam the mussels in a pan with a tight-fitting lid with a finger's depth of water. As soon as they open they are cooked. Throw away any that have not opened and arrange the ones that have on top of the rice.