The name gets applied, though, to two different fish.
Real sole, aka Dover sole, is “Solea solea” and lives in the Atlantic off northern Europe. It’s a flatfish, that grows up to 27 inches (70 cm) long, but the usual size is 12 to 16 inches (30 to 40 cm) long. It lives on the seabed, at depths from 30 to 200 feet (10 to 60 metres), hiding in the sand or mud during the day, emerging at night to feed on small sea life. The skin on the topside is a mottled brown and grey; on its underside, a pale creamy colour.
Most of what is labelled “sole” sold in North America, though, is actually flounder, often the species called “Microstomus pacificus”, fished from the Pacific. If you really want to buy real sole in North America, you need to have a trustworthy fish dealer who won’t try to pass flounder off at higher sole prices.
Sometimes true Dover sole is imported from Europe for expensive restaurants on the eastern seaboard on America. The flavour of real sole is considered superior.
Sole can be cooked whole, or in fillets. The fillets hold together well when cooked.
The fish is easy to skin. The topside skin is usually removed, and the pale underside skin left on.
It is usually cooked very simply to let its flavour come through.
When cooked, the flesh comes easily away from the bones.
Dover sole got called Dover sole as Dover, England was once a primary port for people fishing sole.
The Spanish name “Lenguado” is the same for both flounder and sole.