The Ambassador, London EC1

Number 55 on London's Exmouth Market owes me a good meal. The last one started with oysters rinsed of their juices and flavour, went on to over-cooked prawns, chewy T-bone and limp chips, and finished with a truly awful plate of cream called a strawberry and almond pastry. But that was two years ago. Time heals, and here I am in the same space, although it sure ain't the same place.

Today, the address is in the capable hands of Clive Greenhalgh. He was front of house at The Brackenbury in Chiswick back in the days when it was grooming up some of London gastropubbery's finest young chefs.

Judging by the spare, no-frills look of The Ambassador, Greenhalgh's aims are refreshingly modest. It's a bar with tables: a drop-in diner with lino floors, dark wooden bistro chairs, simple glass white pendant lamps - and an easy-going, mix-and-match, Exmouth Market crowd here to drink, smoke (until next year), natter and eat. You pour your own wine and water, and even roll your own fags, as many of the singleted young ladies are doing in the restricted smoking area at and near the bar. Tousle-haired and loose-limbed, Greenhalgh runs the floor in a relaxed, rambly, good-humoured sort of manner that sets the tone of the place.

What a happy wine list - modern, generous, and well put together in the extreme. Instead of falling back on big names and bigger price tags, it's a New World/Old World romp through some lesser-known, value-for-money labels chosen for interest and flavour. These include a smooth and supple Western Australian Omrah 2004 Pinot Noir and a fruity, fragrant Allegrini 2005 Valpolicella, both at a reasonable £19. There is even a charming seasonal slant to the list, with a special section that highlights "spring" wines - an Austrian Gruner Veltliner and a chilled Italian Lambrusco - chosen to complement both the warmer weather and the lighter, brighter food of spring. If you want to know more about the wines, just ask. Greenhalgh has plenty to say.

The food is in the equally capable hands of Tobias Jilsmark, who previously cooked at La Trompette and The Waterway. His is a fiercely seasonal, produce-driven menu full of big, ballsy flavours in dishes such as casserole of squid and pig's cheek, braised pork belly with calves' sweetbreads, and wild mushroom and macaroni gratin.

I start with a little bar plate of ham hock ballotine (£4) served as two meaty, carrot-studded rounds and a splodge of jammy, caramelised onion. It tastes lighter and fresher than it looks, and is a perfect kick-start to the meal, especially with a half pint of nicely cold Budvar (£1.80).

Then comes greatness in the shape of a thick, room-temperature slab of foie gras and chicken terrine (£7.50). A pinkish, wobbly top of lush foie gras melts into a bottom layer of well-seasoned, juicy chicken bits pressed together like a compacted car body. The combination is thrilling: rich without being overwhelming and full of natural, undiluted flavours that haven't been chilled into submission. Compared to the rush of the terrine, cured salmon with thinly shaved fennel and cucumber (£5.50) is merely good. A little less firmness, a little more salmon, and a little hot toast on the side, and it would be better.

We are soon back to greatness with the main courses. A plump finger of moist, poached halibut (£17) snuggles up to a wedge of hispi cabbage in a clever juxtaposition of earthy and refined flavours. I can't remember cabbage ever tasting this good, which probably means it was cooked in very good stock. In addition, a velvety orange carrot purée - studded with sweet little Chantenay carrots - broadens the appeal of the dish, and a scattering of Alsace bacon adds a nice smoky note.

Then there's the Haughley Farm chicken breast (£14), which is everything a chicken breast should be and rarely is - crisp-skinned, relaxed and full-flavoured. Fresh morels and wilted wild garlic leaves, like garlicky, mossy, spinach, are textbook examples of companion plating. There are side vegetables on offer, but main courses are complete in themselves, making them very good value.

A plate of well-kept French cheeses (Roquefort, brebis and Tomme de Savoie, £5) to finish is good, and a rustic pud of quince and apple terrine with honeycomb brûlée (£4.50) is dense and unexciting.

But I have already been to the mountaintop in the form of some of the most assured, together and unfussy cooking I have encountered in some time. Jilsmark's food is sweet-tempered and full of subtle harmonies, while feeding the hordes for a decent price. It's also great to come across an accessible wine list, with wines at correct temperatures.

A score of 16 might seem high for such a modest, casual establishment, but this is casual in the best possible sense, teamed with confident craft and food that harmonises texture, sweetness and acidity. OK number 55, let's just say we're square now. s

Scores 1-9 stay home and cook 10-11 needs help 12 OK 13 pleasant enough 14 good 15 very good 16 capable of greatness 17 special, can't wait to go back 18 highly honourable 19 unique and memorable 20 as good as it gets

16/20

Scores: 1-9 stay home and cook 10-11 needs help 12 OK 13 pleasant enough 14 good 15 very good 16 capable of greatness 17 special, canÕt wait to go back 18 highly honourable 19 unique and memorable 20 as good as it gets

The Ambassador, 55 Exmouth Market, London EC1 Tel: 020 7837 0009

Lunch served daily, dinner served Monday to Saturday. Around £75 for two including wine and service

Second helpings: More eateries with top-value wine lists

Crooked Billet 2 Westbrook End, Newton Longville, Buckinghamshire, tel: 01908 373 936 There is real value for money in the 300-strong wine list at John and Emma Gilchrist's pretty thatched pub - and flexibility too, with most of the wines available by the glass. Check out the "Most Popular Wines" page - there's good reason.

Read's Mackanade Manor, Canterbury Road, Faversham, Kent, tel: 01795 535 344 Let's encourage this trend towards fine, fairly priced wine lists with "Best Buys" sections for the budget-conscious wine lover. Especially when they come with a comfortable one-Michelin-star restaurant in an elegant Georgian townhouse, and David Pitchford's fine touch in the kitchen.

Enoteca Turi 28 Putney High Street, London SW15, tel: 020 8785 4449 Giuseppe Turi's 16-year-old "wine library" combines authentic regional Italian cooking with a mind-boggling range of Italian wines. For those still feeling their way through the Italian repertoire, every dish comes with an affordable wine recommendation.