Fish fillets and steaks, cut from whole fish, are available fresh or frozen. Fish with flaky flesh include flounder, lingcod, red snapper, rock cod, salmon, sea bass, sole, trout, and turbot. Those with firm flesh include halibut, mackerel, monkfish, shark, swordfish, and tuna.
To test fish for doneness:
Slit the fillet or steak at the thickest part with the tip of a small, sharp knife. If properly cooked, the flesh will appear just opaque but still moist.For specific types of fish, see anchovies, cod, flounder, halibut, lingcod, mackerel, monkfish, red snapper, rock cod, salmon, salt cod, sardines, sea bass, snapper, sole, swordfish, trout, and tuna.