Flounder encompasses several American flatfish species like gray, petrale, lemon sole, dab, fluke and plaice. The types are interchangeable when cooking, with the exception of Dover sole, a flatfish found only in European waters with firmer and tighter flesh than American flounder.
Flatfish are bottom-dwellers with wide, flat bodies. They swim on their sides and have both eyes on one side of their heads. (Halibut are larger flatfish.)
Flounders are sold as a whole fish or thin fillets and usually skinned, although the skin is edible. Whole flounder is good sautéed, steamed or roasted. Fillets are excellent sautéed with a coating of flour or light breading to crisp the soft flesh and prevent them from falling apart.
Substitute any flatfish.
Halibut, the largest flatfish in the ocean, grows up to 9 feet long. Closely related to flounder, these fish are wide, flat bottom-dwellers that swim on their sides and have both eyes on the same side of their body.
They can grow to be up to 600 pounds, but their weight averages about 5 to 10 pounds. Halibut meat is lean, white, dense and finely textured. It is tender and mild-flavored when cooked.
Halibut is available farm-raised or, sometimes, wild. Alaska produces about 80 percent of Pacific halibut, and peak season runs from April through October. It is sold whole, as fillets or steaks, usually without its edible, but not very tasty, skin. At the market, look for white, glossy flesh, avoiding any cuts that look dull, yellowish or dried out. Halibut also retains moisture well when frozen.
It can to be prepared using a variety of cooking methods such as sautéing, grilling, broiling, roasting, steaming or poaching, but the lean meat dries out quickly if overcooked. Similar fish include sea bass, snapper or grouper.
3. Mahi Mahi
Mahi mahi has long been known as dolphin fish because it swims next to boats like dolphins often do. The fish is now known by its more consumer-friendly Hawaiian name, which means "strong strong."
Found mostly in the South Atlantic and Caribbean, mahi mahi's fast growth rate ensures an abundant supply. They average 3 to 6 pounds, but the largest can reach 70 pounds. The best quality and most expensive varieties are caught by troll fishing in Hawaii.
Mahi mahi is a beautiful fish, iridescent blue-green and gold-colored, and bright skin is a good indicator of freshness. It is sold filleted or in steaks, and the meat should be firm and pink to beige in color. Darker portions of flesh have a stronger flavor and can be trimmed off, and the thick skin should be removed before cooking, unless grilling or broiling.
Cooked mahi mahi flesh is lean and sweet with a firm texture and large flakes. It is a popular choice for grilling because it doesn't fall apart easily. It can also be sautéed, broiled, baked or used in soups, and its mild flavor works well with Caribbean and Pacific Rim spices. Similar fish include swordfish, tuna or striped bass.
Because of high mercury levels, limit children's consumption of mahi mahi to three meals a month or fewer.
Monkfish is known for its huge head and mouth, and its tight, meaty white flesh that is often compared to lobster meat. It's commonly used in French cuisine, but it has only recently become popular in America.
Only the monkfish tail is edible, and it's sold whole or filleted. Any gray or tan membranes should be removed before cooking. The flesh is bright white, lean and mild-tasting.
This versatile fish can be prepared using almost any cooking method, and it can be served in soups and stews. Its lean flesh tends to dry out if overcooked. Monkfish has a unique flavor and texture, but you can substitute snapper, sea bass, halibut, mahi mahi or sea scallops.
5. Red Snapper
Hundreds of snapper species exist, named after their "snapping" teeth. American red snapper is a reef fish found in the Caribbean and along the mid-Atlantic coast. Its fine texture and sweet, delicate flavor earns it praise.
Buy snapper from a trusted source and ask questions, since the name "red snapper" is sometimes used to refer to similar but less desirable fish like the West Coast rockfish. It is sometimes difficult to see the difference between true red snappers and other red fish.
Red snappers have bright red or metallic, pink skin and average 4 to 6 pounds, but they are usually sold in the 1-1/2 to 3-pound range, whole or filleted. Fillets should always be sold with their tasty skin, which holds the delicate flesh together. Whole fish should have clear, bright red eyes.
When cooking whole, score the fish two to three times crosswise through the thickest flesh, near the head. Whole fish can be broiled, grilled, pan-fried, steamed, baked or deep-fried. Fillets are good pan-fried or steamed. Similar fish include sea bass, halibut or striped bass.