Pakistan's 1,000km coastline along the Arabian Sea means fish is central to the food culture of Karachi and Sindh, even if it's overlooked in international representations of Pakistani cuisine. The fish curries here are coastal in character — lighter than meat curries, built with tamarind for sourness, fenugreek seeds for a distinctive bitterness, and generous turmeric that turns the oil golden.
Use the firmest white fish you can find: rohu, king fish (surmai), or pomfret are the Karachi classics. Sea bass, haddock, or cod work well in the West. Cut into thick steaks or large chunks — the fish should hold its shape during cooking.