Pungent fermented shrimp/krill paste. Smells terrible, tastes essential. The hidden depth of half of Southeast Asian cooking.
Each coastal Southeast Asian culture has its own version — Thai kapi, Malaysian/Indonesian belacan, Vietnamese mắm tôm, Filipino bagoong, Cambodian prahok.
Funky, salty, deeply marine. Always cooked, never eaten raw.
Mashed into Thai curry pastes. Fried with sambal in Malaysia. Mixed into Vietnamese dipping sauces. Dropped into Cambodian fish soups.
Refrigerated paste in plastic tubs (Thai), dry brick form (Malaysian). Pantai is reliable for Thai, Mak Nyonya for Malaysian. The paste should look brownish-purple, never grey or black.
Anchovy paste + a pinch of dried shrimp powder. Not equivalent but functional.
Refrigerated, sealed in a separate plastic bag (the smell migrates). Indefinitely stable.