Mix the salt with crushed garlic, and rub this mixture all over the duck legs. Place them in a shallow dish with the bay leaves, thyme, peppercorns, and shallots.
Cover the dish and refrigerate for 24-48 hours. This curing process is essential for developing flavor and ensuring preservation.
After curing, rinse the duck legs thoroughly and pat them completely dry. Discard the herbs and aromatics.
Preheat your oven to 250°F (120°C).
Place the duck legs in a heavy-bottomed pot or Dutch oven, and cover completely with duck fat. The legs should be fully submerged.
Cook in the oven for 2.5-3 hours, or until the meat is very tender and easily pulls away from the bone.
Let the duck cool in its fat to room temperature.
To serve, remove the legs from the fat and crisp the skin in a hot skillet for about 4-5 minutes on each side.