Turbot is a large saltwater flat fish native to the North Atlantic, Baltic, and Mediterranean seas. It can be a little pricey (about £30 per kilogram), but the meaty, firm, white flesh is delicious. Whereas pan-frying and grilling can dry the fillets out, cooking them sous vide with Joule will enable you to lock in moisture and retain its mild flavour (complemented well by champagne, white wine, and lobster sauces). Note: If cooking at the highest temperature, do not sear your fish.
When shopping for turbot, try to buy fish that has been sustainably caught in British waters, such as off the coast of Cornwall. Stocks of this fish are being depleted so this “King of the Seas” is best eaten on special occasions. (You can also buy farmed turbot, but wild tastes superior.) What goes well on the side? Try mussels and salsify, pearl barley risotto, prawns and braised fennel, or a simple parsley or hollandaise sauce.