In France, a blend of finely-chopped parsley, chives, tarragon and chervil is used to enhance delicate dishes, while across the border in neighbouring Spain fresh parsley and grilled fish is a lunchtime staple. Earthy oregano, meanwhile, seasons many of Mexico’s favourite dishes, from pozole to black beans, while fresh basil is synonymous with rustic Italian cooking. Herbs have been used for thousands of years to add flavour and fragrance, enhancing virtually any dish, be it sweet or savoury. Whether we use them in oils to finish dishes, scatter them into salads or toss them with roasted vegetables, they are a kitchen mainstay, at the heart of recipes from every corner of the globe.

Chef Luke Farrell knows a thing or two about the power of herbs. In his custom-built tropical greenhouses at Ryewater nursery, in Dorset, he has built a living encyclopaedia of exotic herbs and spices, inspired by his travels across the likes of Thailand, Malaysia and Vietnam. There are delicate leaves, varieties of basil and lemongrass, as well as gingers, citrus fruits and chillis, most of which are near-impossible to buy in the UK and would struggle with the long journey from their home countries. Over the years, Luke, who splits his time between Thailand and the UK, has supplied the likes of Kiln and The Begging Bowl, and now focuses on his own restaurants Plaza Khao Gaeng and Speedboat Bar in London, which celebrate southern Thai cooking. 

Herbs underpin Southeast Asian cooking; they top soups and stir fries, are ground into pastes and can be found served as sharing herb plates. While they add flavour, they also have a hand in cooling the spice of fiery dishes from cuisines like Thai, which deliver particularly punchy heat. ‘The dishes are designed around herbs,’ Luke explains. ‘The food is designed to pull rice and herbs into you – that’s why the curries are so extremely hot. They are rice and herb-pullers.’ Here, Luke introduces us to the herbs he’s most excited about at the moment.

Though we’re familiar with cashew nuts in our cooking, in parts of Asia cashew leaves are also an important addition to recipes. Regularly spotted on tables across southern Thailand, they stimulate digestion and, when eaten on their own, have a bitter taste (and a texture which is not dissimilar to, but tougher than, spinach). When eaten with other foods, they take on a sweeter flavour, Luke says, cooling spicy dishes and cutting through rich flavours like coconut milk, which is widely used in Thai cooking. Though they can be eaten fresh, like lettuce leaves, dipped in spicy sauces, they are also often pounded and used in salads, paired with an acidic dressing (similar to a slaw, he says) or in Thai chilli sauce nam chup. In Malaysia, they are included in ‘ulam’ table salads and used as a garnish for fish and sambal dishes. Luke says they have recently started to germinate in his greenhouses and will soon be weaved into dishes at his restaurants. While they are easy to get hold of dried in the UK, it's much trickier to find them fresh.

Most of us will have enjoyed the sweet acidity of tamarind in our cooking, whether it’s been in vibrant curries or sticky, glazed meat. The tamarind tree is native to Asia and Africa, and produces pods of fruit which are sweet and sour when ripe (and even more sour when unripe). It holds a particularly prominent place in Thai and Indian cooking, and in recent years has become an increasingly popular ingredient in UK kitchens. The leaves – or fronds – are lesser-spotted in the UK, but act as a great souring agent (younger leaves are less sour and more tender) for curries, stews, chutneys and sour tom yum-style soups. They can be pounded into a paste, or pickled (a particularly popular method in India). They are, unsurprisingly, hard to get hold of fresh here – it’s always worth visiting your local Asian supermarket – but Luke says, with a bit of research, tamarind is surprisingly easy to grow at home.

Ming aralia – or polyscias fruticosa – is native to India but grown around Southeast Asia. In Thailand, it is called lep khrut (translating to ‘Garuda claws’). It’s used in leaf salads, eaten raw with a spicy dip, steamed, boiled in curries and often fried, either as tempura or with prawns in fritters. It has an aromatic flavour, reminiscent of parsley. Cooks tend to use the younger leaves and shoots, which are less stringy than more mature ones. It’s a perennial plant, which is easy to buy in the UK as a house plant, but, of course, do your research first if you're intending to use it in the kitchen.

Arguably the most obscure (and hardest to track down) on this list, Micromelum minutum (it goes by other names elsewhere around Asia, including limeberry, sesi and samui) is a species of small tree, or shrub. It has scented flowers and oval-shaped berries which grow in dense clusters, but the leaves – which look similar to curry leaves – have the warming spicy sweetness of clove. Enjoyed as part of a herb plate in southern Thailand, it pairs well with dishes using coconut milk, Luke says, as well as seafood and fish. He also uses it alongside meats with grassier, gamier flavours like lamb and goat.