The art of oils

AROMATIC oils have been used to flavour foods for at least 1,000 years. While the Chinese have been using sesame oil, intensely flavoured oils have been prominent in the Mediterranean, as well as hazelnut and walnut oil in the south of France.

However, oils that have been infused with other flavours have been trickling in to the UK market only in the past 10 years. More recently, though, the floodgates have opened and now there is no such thing as an oil too obscure to be in demand.

John Wood, executive chef at Chapter One in Locksbottom, Kent, has been using flavoured oils for the past eight years in place of cream and butter, because he believes they enhance the flavour of ingredients. "Flavoured oils give dishes a lift. They bring lightness and still add taste," says Wood, who blends them into stock-based sauces in place of butter to emulsify the sauce - such as wild mushroom oil in chicken stock - and uses them for marinating meat or fish to infuse a bit more flavour.

Oil makes an excellent medium for diffusing flavour, as most aromatic "flavour" compounds are highly oil-soluble. But because heat destroys these aromas, flavoured oils should be added at or near the end of cooking.

There are three basic types of flavoured oils: infused, like herb, truffle and mushroom; seed and nut oils; and citrus oils, made by pressing whole fruits for the essential oils in their skins, usually as a component of flavoured olive oils.

Mark Leatham of Leatham's Larder finds that most chefs infuse their own oils and only buy the ones that they cannot practically make themselves, such as truffle oil. However, basil oil is a big seller for Leatham's because making it is not as easy as it would seem.

intense aroma

"Basil oil is not very easy to make because of the high water content in basil leaves," explains Leatham, who sources his basil oil from Genoa, "where Europe's best basil is grown". After harvesting it between June and September the basil is stored in the locally made taggiasca olive oil (a mildly flavoured olive oil). "That 'storage' oil has an incredibly intense aroma of basil," says Leatham.

Basil oil is the chefs' darling at the moment. London chef-proprietor Giorgio Locatelli makes most of his own flavoured oils, but he buys Tornatore Extra Pesto Olive Oil (Italbrokers) for its intensity of flavour. Locatelli finishes a tortelloni of prawns and basil with jus de moules and basil oil on top of a light tomato sauce. His baked red snapper is served with basil pommes purée - the mash is made with butter but finished with basil oil at the end - and he also uses a few drops to colour the edge of the plate.

In Wells-next-the-Sea, Norfolk, Moorings chef-proprietor Carla Phillips uses basil oil for a vinaigrette dressing that she pours over a salad of finely chopped fennel, potato, pimento and salami, and says that basil oil makes a good base for mayonnaise.

flavour of the month

Rosemary and garlic oil is another "flavour of the month" and one that a lot of chefs make themselves. At London's Cantina del Ponte, head chef Jonathan Nicholson serves rosemary and garlic oil with mackerel and lyonnaise potatoes, with roast garlic and bacon lardons as a garnish, and says that it works particularly well with most grilled or sautéd fish. Phillips says it is delicious over gratin potatoes, "and I always have some on hand to make vegan mashed potatoes", while Colin Clydesdale, chef-proprietor of Stravaigin in Glasgow, seasons clapshot (mashed potato and turnip) with it. This is then accompanied by lamb or sea bass.

Walnut and hazelnut oils are also appearing in a lot of interesting ways. One of Locatelli's inspired salads is made up of layers of carta da musica, the sheet-music-thin Sardinian bread, layered with pecorino and rocket salad with pears, dressed with a walnut oil vinaigrette and served with walnut bread; and David Richards, chef at the Old Bell in Malmesbury, Wiltshire, accompanies goats' cheese soufflé with roasted hazelnuts and hazelnut oil on salad greens.

Roasted pumpkin seed oil is new to the UK market and is a traditional product from the Styria region of Austria. Its strong, distinctive taste is very nutty and a bit like heavily flavoured olive oil mixed with sesame seed oil; it has a dark green-brown colour. Georg Fuchs, executive chef at London's Langham Hilton, hails from Styria, and uses the oil to great effect in a cold salad of pickled beef and with pan-roasted pumpkin as a base for sea trout (see recipe, page 36). This oil is a superior dressing for potato salads and is also used in Austria for pumpkin cake.

The overuse of truffle oil is one of Locatelli's pet hates. "When you use truffle oil it has to be the only other strong flavour in that dish," he says. He serves carpaccio on a bed of rocket, finished with white truffle oil (Tornatore brand from Italbrokers), Parmesan and gratings of sea salt and pepper.

Richards makes his own morel oil with air-dried trimmings, immersing 8oz morels into one pint of oil (75% olive oil, 25% vegetable oil) and uses this to finish off risotto with mussels and sun-dried tomatoes. Fellow Wiltshire-based chef Chris Suter of Bishopstrow House in Warminster, drizzles cäpe oil on chargrilled chicken with leeks and girolles, and orange olive oil (from the Olive Grove, Bristol) on sea bass with grilled artichokes, for which he also cooks tomatoes with olive oil, basil, shallots and garlic.

chefs' own creations

Chefs have also come up with a lot of their own flavoured oils to suit their particular dishes. Nicholson makes lobster oil (see below), which he uses to make a mayonnaise for lobster and mango salad (see recipe on page 35) and in dressings such as béarnaise and hollandaise. And he makes tapenade oils with green or black olives as a dressing.

Phillips makes curry oil with mild Madras powder soaked in sunflower oil for a couple of weeks, and uses it in vinaigrettes made with lime juice and zest to dress fatty roasted or grilled fish, like salmon or mackerel. Wood makes several vibrantly flavoured and coloured oils, such as beetroot oil (add beetroot, sugar, red wine vinegar and shallots to vegetable oil, infuse slowly in a bain-marie, blitz in a blender, allow to separate and let drip through muslin) which is mixed with a lime juice dressing for home-made hot-smoked salmon with warm potato salad.

For saffron oil, Wood sweats the threads in vermouth then lets them infuse in oil in a bain-marie. He serves this oil with Earl Grey tea-smoked duck on a bed of couscous salad with rocket, and for desserts he makes a raspberry oil (raspberries blitzed in vegetable oil and allowed to drip through). At Stravaigin, Clydesdale makes cinnamon stick oil and serves it with roast quail and other game birds for a deep aromatic glaze. n