The French cooking method that slowly cooks meat in its own fat is confit.
In a traditional meat confit, the meat is salted, seasoned, and slowly cooked while submerged in rendered fat at a low temperature. The gentle cooking makes the meat tender, while the salt and fat historically helped preserve it before refrigeration. The word confit comes from the French confire, meaning “to preserve.”
Duck and goose are the classic meats used for confit, especially in southwestern France. Duck confit is strongly associated with Gascony and often appears in cassoulet. After cooking, the meat may be stored under its fat and later reheated or fried until the skin becomes crisp.
Confit is not the same as deep-frying: the food cooks slowly at a much lower temperature. Modern cooks also use the term for vegetables such as garlic, onions, or tomatoes cooked gently in oil, although meat confit is the traditional French usage. Poaching uses liquid, while braising combines liquid with moist heat.