Beautiful bergamots: The fruit is the chefs' citrus of choice this spring

We're playing pass the "orange", perched on stalls at the counter of James Knappett's intimate Kitchen Table within his Bubbledogs restaurant, where he creates tasting menus in full view of his guests. Except this is not a variation on the nostalgic adolescent game of transferring oranges under the chin and it is not a conventional citrus.

Knappett likes to challenge his guests with unfamiliar ingredients and new flavours. They inhale appreciatively the heady, familiar yet elusive fragrance of the orange-shaped yellow/green skinned citrus quizzically. This is Catalan bergamot, a sour orange crossbreed, closer to a lemon, and it is better known for giving Earl Grey its distinctive taste, though stealthily it has become the citrus of choice this spring, certainly upstaging the blood orange among chefs and fanatical foodies.

Knappett adds bergamot aromatic rind and acidic (yet sweeter and more delicate and floral than lemon) juice to flavour yoghurt and mixes with charred cucumber, fresh dill and dill oil, then serves it with raw salmon topped with crispy salmon skin. Its citrus element is "softer" than lemon and it is unwaxed and untreated because the skin is so important, so the flavour is really true and clear. It is an excellent partner to fish. Well in the vanguard, Ashley Palmer-Watts's launch menu at Dinner by Heston Blumenthal featured bergamot – and lime-cured mackerel – and Watts is now working on a new dish highlighting bergamot as he can't get enough of its "beguiling intensity".

Tweeting about my discovery of the manifest charms of bergamot, I unleashed a swathe of creativity. The Renaissance Girl (twitter.com/Bebejax) adds bergamot to Asian-style marinades with soy, ginger and rice wine vinegar and cautions: "It is important to get the balance right as too much can be intoxicating. I tend to use bergamot alongside other citrus to subtly up the citrus quota." Bergamot juice can also be substituted for vinegar in vinaigrettes for a perfumed tartness.

Persian cookery writer and private chef Sabrina Ghayour explains bergamot is an essential ingredient in Persian cuisine, "as we Persians love all things sour and bitter". She's been experimenting with honey-soaked bergamot flesh with pork fillet or chicken, candied bergamot in exotic salads and even adding bergamot zest to madeleines. Bergamot is likely to feature in her Norooz Persian New Year dinner (celebrated on the first day of spring) on 22 March at Peyton and Byrne at The National Gallery, in both savoury guises and preserves served with petits fours.

Private chef Bruno Breillet (twitter.com/BrunoFrenchBake) adds bergamot zest to meringues and finds it lifts marmalade to another level (rinse the rind before use to tame its tartness). Bergamot and mint make for a refreshing sorbet at London's hottest restaurant Dabbous, a sure sign that it is the citrus of the moment. Ollie Dabbous advises to use the zest more like a spice alongside lemon juice to subtly up the zing. Bergamot even features as one of the icing flavours on the old-fashioned doughnut menu at The Electric, says Soho House executive chef Jake Rigby-Wilson: "The bergamot's vibrant, distinctive aroma is transforming and confounds expectations, which makes it such a pleasure to use."

Patricia Michelson of La Fromagerie, one of the few retail stockists of bergamot, recommends making bergamot syrup to add to prosecco or sparkling water. She also makes a variation with warm spices of cinnamon, cardamom, vanilla, star anise and chilli to glaze lemon (and bergamot) polenta cake. Michelson even likes to use slices of bergamot in Earl Grey and single- estate Ceylon teas, besides infusions such as Verbena and Chamomile.

I'm intrigued to discover that, historically, Calabrians favoured bergamot as a fruit known to have a beneficial effect in promoting cardiovascular health. It has an exceptional content of citrus polyphenols, which also give the fruit its bitterness. Recent Italian medical research reaffirms that bergamot capsules of extract and pulp may be helpful in inhibiting cholesterol biosynthesis with a natural statin-like effect in reducing bad and raising good cholesterol and lowering blood sugars.

Though for a more immediate lift bergamot is, according to Nick Strangeway, consultant to Mark's Bar, the distinctly nuanced flavour of the moment for cocktails: he recommends steeping the zest in high-proof alcohol to make bergamot bitters, infusing it in vodka or gin or simply using the juice to make a Sidecar or Julep of extraordinary intensity and claims a Martini is incomplete without a twist of bergamot. Will James Bond insist on the enigmatic bergamot in his next movie?

Bergamots are available from natoora.co.uk, wholefoods.co.uk, solstice.co.uk, lafromagerie.co.uk. Other exotic citrus by special request only from natoora.co.uk.

Bergamot sorbet

Serves: 4-6 people

The refreshing, fragrant flavour of bergamot makes the perfect palette cleanser so try this sorbet at the end of a rich meal.

Ingredients

4 Natoora unwaxed bergamots, juiced and zested
150g caster sugar
2 egg whites
300ml water

Dissolve the sugar in the water over a low heat, before gently bringing to the boil for a couple of minutes. Remove from the heat and add the bergamot zest, cover and leave to infuse for half an hour.

Add the bergamot juice to the sugar syrup, then strain and place in a shallow container. Freeze for 2 hours until slushy.

Whisk the egg whites until fluffy and mix into the sorbet. The sorbet must be only semi-frozen to be able to do this. Freeze for at least 6 hours. Remove from the freezer 10 minutes before serving.

More exotic citrus fruits to try

CEDRO

I'd always known cedro as etrog lemon, an essential part of Jewish Sukkot rituals, and was bemused to come across a Yiddish expression for something that has no value as being like "an etrog after Sukkot". How very misguided. Its elongated lemon shape is awesome – sometimes as large as a melon – with a textured yellowy-green skin. Cedro has an exceptionally large ratio of soft, white, surprisingly sweet pith that can be used with the bitter-sweet, prized rind. In Sicily, where cedros are grown, it is thinly sliced and sprinkled with salt or sugar as a snack with aperitifs (or candied) or combined with fennel in a salad.

DIAMANTE CITRON

Chris Golding at Apero at The Ampersand is another chef who takes great pleasure in using ingredients that are a talking point for guests. He uses diamante citron, sweeter than a conventional lemon and similar to a cedro. He adds its juice besides lemon to cure wild sea bass served with fennel and purple potatoes.

BUDDHA'S HAND

A fragrant citron whose fruit is segmented into finger-like sections. The origin of Buddha's hand is north-eastern India and China though it is now grown in California. It has no juice and is mainly valued for its zest. The inner white pith is not bitter so the fingers can be longitudinally sliced, peel, pith, and all, and used in salads. Not least by Michel Roux Jnr at Le Gavroche in a crab salad with spring onions, roasted hazelnut oil and spicy tomato mousse.

SHATKORA LEMON

Indian citrons identifiable by their large "wings" on the stalk attaching the leaf to the stem, they have smooth yellow rind, dry, greenish-yellow flesh and a very sour, bitter juice. At Trishna, segments of Shaktora lemon are added to give extra verve to a masala chicken curry.

LIMEQUAT

Tiny round citrus related to both kumquat and lime. Look for the more yellow-skinned limequat as its intense sourness and tartness is more mellow. Use sparingly in dressings and desserts. Sometimes seen in larger branches of Sainsbury's.

FINGER LIME

The ultimate, decadent citrus burst, often called lime caviar as the interior pulp has a caviar-like appearance and pops and bursts on the roof of the mouth, exploding with vivid lime flavour. Wonderful as a seafood garnish and relatively less expensive than caviar though still a huge treat. Available from efoodies.co.uk