The flavor base of Thai curries — spicy, aromatic stews served over rice — starts with curry paste, a smooth, moist blend that may include shallots, garlic, lemon grass, green or red chiles, cilantro roots, Kaffir lime leaves and peppery, gingerlike galangal.
The distinctive colors of the pastes — red, green and yellow — reflect the specific makeup of each. No one type is the spiciest; the heat depends in part on the number and kind of chiles used. Mellow yellow curry paste, bright with turmeric and other dried spices, is often combined with lamb, beef or potatoes in a heavy sauce. The red paste, rich with dried red chiles, is great with beef, chicken, fish or shrimp. The green paste, with the clean flavors of fresh chiles and herbs, is wonderful with pork and vegetables.
Look for curry pastes in your supermarket’s Asian foods section. If making a vegetarian curry, read labels closely: Some contain shrimp paste or fish sauce, while others are vegan. Store opened paste in the refrigerator for up to 6 months.