Sri Lanka Fish Mustard Curry

Sri Lankan curries have a flavor all their own, and this fish curry shows exactly why. The signature here is mustard, ground and blended with tart lime juice into a paste stirred in at the end, giving the curry a sharp, pungent tang you won’t find in Indian or Thai versions.

The spicing is warm and fragrant rather than fiery: whole cloves, cardamom, a cinnamon stick, and turmeric infuse the coconut milk as the fish gently poaches. Shallots and garlic, fried first, build the savory base.

The clever part is the two-stage coconut milk. Thin coconut milk goes in first to cook the fish through gently, then thick coconut milk, mixed with that mustard-lime paste, is added at the very end and barely simmered. Adding the mustard late keeps its sharp bite bright instead of cooking it dull, and folding the thick milk in last keeps the sauce from splitting. Be gentle once the fish is in so the pieces stay whole. Discard the cinnamon stick and serve it over plain rice, which soaks up the tangy, creamy, golden sauce.

Pro Tips

• Add the mustard-lime paste at the very end and barely simmer. Long cooking dulls its sharp, signature bite.
• Use two consistencies of coconut milk if you can: thin to cook the fish, thick to finish the sauce richly.
• Handle the fish gently once it’s in the pan so the pieces stay intact.
• Use a firm fish that holds its shape, like kingfish, snapper, or tuna.

Variations

• Add curry leaves and a pandan leaf for a more authentic Sri Lankan aroma.
• Stir in a sliced green chili or a pinch of chili powder for heat.
• Use prawns or a firm white fish in place of the fish called for.