Lay the leg portions on a platter, skin side down. Sprinkle with 1 tablespoon of the kosher salt and black pepper. Place the garlic cloves, bay leaves and sprigs of thyme on each of 2 leg portions. Lay the remaining 2 leg portions, flesh to flesh, on top. put the reserved fat from the ducks in the bottom of a glass or plastic container. Top with the sandwiched leg portions. Sprinkle with the remaining 1/8 teaspoon kosher salt. Cover and refrigerate for 12 hours. Preheat the oven to 200 degrees F. Remove the duck from the refrigerator. Remove the garlic, bay leaves, thyme, and duck fat and reserve. Rinse the duck with cool water, rubbing off some of the salt and pepper. Pat dry with paper towels. Put the reserved garlic, bay leaves, thyme and duck fat in the bottom of an enameled cast-iron pot. Sprinkle evenly with the peppercorns and salt. Lay the duck on top, skin side down. Add the olive oil. Cover and bake for 12 to 14 hours, or until the meat pulls away from the bone. Remove the duck from the fat. Strain the fat and reserve. Pick the meat from the bones and place it in a stoneware container. Cover the meat with some of the strained fat, making a 1/4-inch layer. The duck confit can be stored in the refrigerator for up to one month. The excess oil can be stored in an airtight container in the refrigerator and used like butter for cooking. The tinge of duck taste in the oil is wonderful and I use the oil to roast potatoes, cook green beans and panfry veal.
Combine all of the ingredients, except fat, in the bowl of an electric mixer fitted with a dough hook. Beat at medium speed for about 1 minute, or until everything is well mixed. Or use a food processor, taking care not to puree the mixture or let it turn into a paste. The texture should be like finely chopped meat.
Use immediately or place in an airtight container, drizzle some of the reserved fat over the top, and store in the refrigerator for up to 1 week.
Preheat the to 425 degrees F. Season the potatoes with the olive oil, salt and pepper. Place the potatoes on a baking sheet. Roast the potatoes for 45 to 50 minutes or until fork tender. Remove the potatoes from the oven and cool completely. Using a sharp knife, slice, lengthwise, about 1/4 inches from the top. Scoop out the pulp from each potato. In a mixing bowl, combine the potato pulp, rillette, truffle oil and 1/4 cup of the cream. Beat until smooth. Season with salt and pepper. If the mixture is too lumpy, add a little more cream. Spoon the potato mixture into the potato shells. Sprinkle the top of each stuffed potato with the cheese. Place the potatoes on a baking sheet. Bake for about 8 to 10 minutes or until the cheese is melted. Garnish the potatoes with shaved truffles and chives.