Good food comes up from the street level, and many of Thailand’s most popular dishes can be found at the smallest food stalls and restaurants. And there is the influence of China, India, Malaysia and other neighbouring countries. So all these different factors come together under the label “Thai food”, and you will find them in varying degrees at any Thai restaurant you care to visit, anywhere in the world.

One of the most distinctive aspects of the cuisine is its use of herbs and spices. With regard to the spices, some Thai dishes are very hot, but by no means all of them. The herbs have another function, in addition to providing flavour, in that they all have to varying degrees various medical and therapeutic benefits.

Thailand has a long history, going back to ancient times, of the use of herbs for medical purposes, and this in turn has permeated the ways of cooking and preparing food. Coupled with its low-fat qualities and its essential freshness, this helps make Thai food one of the healthiest anywhere.

Another important aspect about Thai food is the hospitality and friendliness, the sheer enjoyment of good companionship and of eating that is such a powerful element of the Thai personality. Sharing a meal is an important part of the day for any Thai person, and meals are very seldom taken alone. That is why all the dishes are generally served at once during a Thai meal, and why there is a communal spoon placed alongside each dish for people to help themselves and to serve others.

A Thai meal ideally is a communal affair, principally because the greater the number of diners the greater the number of dishes that can be sampled. Diners choose whatever they require from shared dishes and generally add it to their own plate of rice. All the dishes are served simultaneously, or nearly so. The object is to achieve a harmonious blend of the spicy, the subtle, the sweet and sour, and a meal is meant to be equally satisfying to the eye, nose and palate.

Thailand is blessed with many varieties of plants, herbs and spices which ensure a balanced diet. Today, visitors can both relish classic Thai menus and the benefits of a natural diet, and study the art of Thai Cooking at several specialist schools in Bangkok and other major cities.

Lemongrass
Lemon Grass is a plant that looks like grass, smells minty and tastes similar to lemon (hence the English name Lemongrass). The thick, woody base of each leaf has long been a key ingredient in Thai cooking. You can easily grow your own by putting a few stems in one inch of water, set in a sunny area, then transfer to your garden after roots start to grow.

Kaffir lime leaves
There is nothing like kaffir lime leaves in the world, as these leaves are just packed with a wonderful strong citrus fragrance. Kaffir lime leaves are used in a wide range of Thai cuisine, notably soups. They contribute astringency as well.

Fish sauce
If there's any one key ingredient that is critical to cooking Thai cuisine, it is fish sauce--for that reason alone, it's difficult to find vegetarian recipes that actually taste like Thai cuisine. Fish sauce provides the salty dimension in Thai cuisine, and it's high in protein as well as minerals and vitamins. It's made from small fish, salt-fermented for a long time, then the juice is extracted and boiled. Good fish sauce should be clear and brownish in color.

Garlic

Most Thai recipes start with sliced garlic frying in oil, and go from there. It would be hard to eat a Thai meal without having garlic in one form or another.

Thai chilli peppers

Thais cannot imagine food without chilli - they sometimes eat them as a snack. Chillis come in different types and sizes. Phrik Khee Noo is the smallest kind, about a centimetre long, but also the hottest. Chopped up in fish sauce, it makes a sauce Thais add to almost any dish.

Coconut milk
Coconut milk is the rich base for many Thai curries and sweet dishes. Coconut milk or 'ga-ti' is traditionally made by mixing the grated meat of a ripe coconut with warm water and then squeezing out the juice. Now there are machines that grate and press coconut to produce the white, sweet-aroma coconut milk. Coconut milk comes in a can for convenient use.

Galangal

A type of ginger, but it's milder and looks different than the usual form of ginger found in supermarkets. Galanga interacts well with the other essential Thai ingredients found on this page. It gives a distinctive, lightly acid taste and helps reduce the smell of meat. Slices of galangal are added to many kinds of curry and soup. Some people crush the bulb and boil it in water as a preparation to cure indigestion or stomach upsets.

Palm sugar
Seeet is a key taste in Thai food, and many recipes use palm sugar. The sugar is harvested from a sugar palm tree, produced from the sweet, watery sap that drips from cut flower buds. The sap is collected each morning and boiled in huge woks on the plantations until a sticky sugar remains. This is whipped and dropped in lumps on cellophane, or filled into containers.

Jasmine rice
Also known as "fragrant rice", Thailand produces rice that's considered the very highest quality in the world. Indeed, much of the rice exported around the world is from Thailand.

Source: http://www.thaicuisine.com/ingredients.html