If you don’t have a water bath or sous vide set up, you can easily confit these duck legs the traditional French way. Heat your oven to 250°F | 121°C. Set the duck legs into a small oven proof pan or baking dish. Cover with either rendered duck fat (that has been melted) or oil, such as a vegetable oil. Make sure the duck legs are fully submerged in the fat | oil, as this is one of the tricks to this cooking techniques, keeping the duck super tender and the skin pale. Place the cooking vessel uncovered into the center of your oven and cook for 6 – 8 hours.
As the duck is cooking in an oxygen free environment, at a high enough temperature, that the fat is sterile after its oven time and temperature. The baking dish would be removed from the oven. Duck confit would be stored on the counter top of many French kitchens. The cooking fat, as it cools, thickens and creates a seal from the air. When a duck leg was needed, the chef would pull one from the congealed fat and fry it. This was before refrigeration and a great way to preserve the meat, in its own fat.
The baking container can be placed into the refrigerator or the duck legs may be removed and put into a container.