Cilantro roots
Often trimmed away before reaching Western markets, cilantro roots provide a moist, pleasant essence to many seasoned pastes. You can substitute coarsely chopped cilantro stems and leaves.

Dried rice noodles
Shelf-stable and quick-cooking, these come in two widths: traditional (similar to linguine) for paht Thai dishes, and wire-thin, often used in soups.

Fish sauce
A clear amber liquid sold in glass bottles, this seasons almost every savory dish made in Thailand, Cambodia, Laos, and Vietnam. Produced by salting down anchovies and other small fish. Vegetarians can omit in recipes by seasoning generously with salt instead.

Galangal
A gingerlike root with intense flavor and sturdy but moist texture. Thais slice it crosswise for seasoning soups and stews, or pound it into pungent curry pastes. Look for it fresh in the produce section, dried into chips, or frozen whole or sliced.

Lemongrass
Fibrous, fragrant, tangy stalks found in the herb section. Discard the top half and outermost leaves; trim base to a smooth surface and use in recipes. Not usually eaten outright, lemongrass is cut into big chunks (easily avoided while eating) or pounded into paste. You can also slice lemongrass paper thin for salads and stir-fries.

Red curry paste
A feisty seasoning made of dried red chilies ground with lemongrass, galangal, garlic, shallots, cumin, coriander seed, and peppercorns. Look for it in small jars and sealed packets at well-stocked supermarkets.

Tamarind chutney or paste
A thick, deep brown, sweet-and-tangy condiment seasoned with cumin, widely available in jars in the Asian section of supermarkets.

Thai chilies
Tiny, fiery, pointed green peppers used whole to infuse soups and curries, sliced in sauces, and chopped in stir-fries. Red and orange when ripe, they freeze well for two to three months. Substitutes include fresh serrano and jalapeño peppers.

Unsweetened coconut milk
Made from finely grated white coconut flesh soaked in warm water and squeezed through a strainer. Available in cans; refrigerate leftovers in a covered jar for one to two days, or freeze.

Wild lime leaves
Also known as mah krud or kaffir lime leaves; often found in the herb section of markets. Aromatic and citrusy, they are torn or cut into pieces, then added to soups and curries; sliced thread-thin, they make an edible garnish. Freeze fresh wild lime leaves for up to three months.