Dry brine the duck. Combine salt and pepper in a small bowl and rub ht mixture evenly over the duck legs. Place them in a bowl or container, cover tightly, and refrigerate for 1 to 2 days.
Preheat the oven to 250F.
Combine duck fat (or fat alternative), shallots, garlic, thyme, citrus peel, cloves, and bay leaf in a dutch oven. Stir over low heat until the fat melts and remove from heat.
Slip the duck legs into the fat. They should be completely submerged. If they are not, add more fat. Cover the pot and transfer to the oven. Cook until the meat is very tender, to the point of falling off the bone when prodded with a fork, about 2 – 3 hours.
When the meat is ready, remove the dutch oven, turn off the oven, and preheat the broiler. Transfer the duck legs to a rimmed baking sheet, skin side up. Broil, turning once, until the skin is crisp and the legs are heated through, approximately 6 to 8 minutes. Be very careful turning the meat as it is very tender.