Flounder can refer to any member of a species of thin, flat fish that swim on one side; both eyes are located on the side that faces up. Size and color vary depending on the species; the downward-facing side of the fish is always pale and nearly colorless.
Flounder have lean white or off-white flesh that’s fine-textured and a mildly sweet flavor with small flakes. The skin is edible, and usually quite tasty.
Whole flounder can be broiled or grilled (you’ll need to use a grill basket); the scales are small and can be scraped off. You can do almost anything with flounder fillets, which are particularly good seasoned, flour-dredged, and pan-fried. Fillets should be cooked briefly (less than 5 minutes) — be sure not to overcook them, or they’ll dry out and fall apart. Once the fillet turns opaque white, it’s done.