Flounder is a broad, flat-bodied bottom-dwelling fish — one of several flatfishes of the order Pleuronectiformes, with the large-tooth flounders of the genus Paralichthys among the most important food species — prized for thin, mild, gently sweet white fillets that turn opaque and flake in moments. Inexpensive, lean and endlessly forgiving, it is a kitchen workhorse: pan-fried in butter, stuffed and baked, or battered for fish and chips.