Rock cod is a saltwater fish with lean, mild-flavored, flaky white flesh. It is available as fresh or frozen fillets.
To test fish for doneness:
Slit the fillet 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, mackerel, monkfish, red snapper, salmon, salt cod, sardines, sea bass, snapper, sole, swordfish, trout, and tuna.