Growing interest internationally in the therapeutic value of herbs and spices has also helped popularise Thai cuisine. A large number are indigenous to the country, and many more have long been cultivated here. They have a long tradition of use in medicine, and consequently cooks understand their therapeutic qualities in addition to their flavours.

Coriander, in all its forms, is probably the most widely used herb. The fresh leaf is used in countless dishes for its distinctive perfume, the roots are pounded together with garlic and black pepper to form a seasoning, while the seeds are both a seasoning and an ingredients.

Basil is another essential, with three kinds being commonly used : the large-leafed sweet basil appears in soups and seafood, The smaller lemon basil in soups and as a salad ingredient, while holy basil is added to stir-fries.
Spearmint leaves are used in salads and often eaten raw, as is mint. Lemongrass is so closely associated with Thai food that it has become a popular restaurant name, and adds its citrus tang to tum yum, the spicy soup that has become the country’s national dish. Lime is squeezed into or over many dishes, while the skin and fragrant leaves of the kaffir lime are used as an ingredient and a garnish.

Ginger is fresh or powdered, while its close relative, galangal, adds its rooty texture to soups and curries. Another member of the ginger family, turmeric, adds its bright yellow-orange colour to southern Thai cooking. Cumin, cinnamon and cardamom have migrated from India, and find their way into curries. Large amounts of garlic are used, along with shallots. Spring onions are eaten raw, or as an ingredient.
Pandan leaf is used as an attractive wrapping for seasoned morsels of chicken or pork rib. Peppercorns are believed to have been the main sourceof heat before chillies arrived in Thailand, and are added whole while still on the stalk, or dried and ground as a seasoning.

Jasmine essence, lily buds, morning glory, cloves, saffron, sesame, and many other herbs and spices that add flavour, aroma and texture, all find their way into Thai cuisine in some form, adding to the healthy and nutritious quality of a meal.