When I make a rempah, my food processor whirls with a mixture of garlic, ginger, chiles or chile paste, and nuts (typically candlenuts, but macadamias and peanuts will do as well). Traditionally, the pungent, savory backbone of the flavor comes from belacan, a fermented shrimp paste that must be toasted before use, though fish sauce is a common alternative in the States, where it's easier to find. Other common additions include tamarind, lemongrass, palm sugar, or sweet soy sauce. Fresh turmeric, which has a warm, refreshing flavor, gives the paste its tell-tale color and lemony brightness. The rempah is then browned in a skillet, enhancing its flavor dramatically, before finally being combined with vinegar to create the pickle's brine.