In Thai curry, curry paste is commonly combined with coconut milk or water.
Thai curry is a broad family of dishes rather than one fixed recipe. Curry paste may be loosened with coconut milk for a rich, creamy sauce, or with water for a lighter, more broth-like preparation. The choice depends on the curry style, region, and available ingredients.
Many Thai curry pastes contain fresh chilies, garlic, shallots, lemongrass, galangal, shrimp paste, and aromatic leaves or roots. The paste is often fried first so its aromas develop before liquid and the remaining ingredients are added.
Coconut milk is especially associated with familiar central and southern Thai curries, including red and green curry. Northern Thai cooking includes many watery curries without coconut milk, partly because coconut palms grow poorly in the highlands. Water is therefore not a substitute added only in emergencies; it is a standard foundation for numerous Thai curries.