Thai food uses a variety of unique flavors, plants, and spices that you won’t find anywhere else. Here are some of the most common ones.
Chilies: More than 10 types of chilies are used in Thai cooking. They vary in size and color, but all are used for spicy flavoring and decoration. They are the main ingredient of chili paste. Though not native to Thailand, the Thais have taken to chilis in spades. There are certain types of chilis for certain dishes and ONLY those chilis may be used
Sweet basil or Thai basil. A sweet basil similar to the kind used in Italian pasta and various European tomato dishes. Used as a vegetable and for flavoring.
Lemon Grass. This plant looks like coarse grass and has a lemony scent. The lower part of the stalk is used for flavoring mainly, but also used as an ingredient in curry paste and certain dishes–the most famous is Tom Yom. Also planted to repel insects.
Fish Sauce: While not a spice, a bottle of the ubiquitous nam pla is found on every table. Made from fermented fish, nam pla is used instead of salt. It can also be used in place of anchovy paste for the Unami effect. Use sparingly; a teaspoon goes a long way.