The ingredients for Thai peanut sauce are dry roasted peanuts, garlic, soy sauce, sesame oil, brown sugar, fish sauce, tamarind paste, cayenne pepper and coconut milk. Vegetarians can substitute soy sauce for the fish sauce, if they prefer. Lime juice can also be used in place of the tamarind paste.
Place one cup of peanuts, two cloves of minced garlic, 1/3 cup of water, 1/2 teaspoon of soy sauce, 2 teaspoons of the sesame oil, 2 tablespoons of the brown sugar, 2 tablespoons of the fish sauce, 1/2 teaspoon of tamarind paste or lime juice, 1/2 teaspoon of cayenne pepper and 1/3 cup of the coconut milk into a food processor. Blend the ingredients together until they are completely incorporated and the sauce is smooth. Runnier sauce is made by adding extra water or coconut milk to the sauce.
Taste the sauce before serving it. Add more sugar for a sweeter sauce, or more soy sauce if the sauce is not salty enough. Add a small amount of lime juice to the sauce if it is too salty. The sauce thickens as it sits at room temperature. Add a small amount of water or coconut milk to the sauce to thin it out again. The peanut sauce can be stored in a covered container in the refrigerator for up to two weeks.