Mackerel is a saltwater fish, related to tuna, with oily, rich-tasting, pale flesh. Mackerel fillets or steaks are available fresh or frozen.
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 other types of fish, see anchovies, cod, flounder, halibut, lingcod, monkfish, red snapper, rock cod, salmon, salt cod, sardines, sea bass, snapper, sole, swordfish, trout, and tuna.