Pat the duck legs dry with paper towels and rub them thoroughly with the coarse sea salt, crushed peppercorns, garlic, thyme, and crumbled bay leaves.

Place the seasoned duck legs in a glass dish, cover, and refrigerate for at least 12 hours (or up to 24 hours) to cure the meat.

Preheat your oven to 225°F (110°C).

Remove the duck legs from the refrigerator, rinse off the salt and seasonings thoroughly under cold water, and pat them very dry again.

Place the duck legs snugly in a baking dish or Dutch oven, skin side up.

Pour the melted duck fat (or lard) over the legs; they should be mostly submerged to ensure tender cooking.

Cover the dish tightly with foil or a lid and bake in the preheated oven for 3 to 4 hours, until the meat is extremely tender and pulling away from the bone.

Remove the duck from the fat and transfer to a wire rack or clean baking sheet.

Increase the oven temperature to 400°F (200°C) or turn on the broiler.

Roast or broil the duck legs for 10-15 minutes until the skin is deep golden brown and crispy.

Serve hot, garnished with fresh parsley, alongside roasted potatoes or a fresh green salad.