Special equipment: a 32 cm (12- to 13-inch) terrine mold
Preheat the oven to 350 degrees F.
Remove the meat from the duck breasts and legs (you should have about 20 ounces). Place the duck meat, bacon and ground pork in a food processor; process until all the meat is cut into small pieces. Transfer to a large bowl. Add the cognac, salt, pepper, shallots, egg and parsley to the bowl and mix until evenly combined.
Line the bottom of a 12- to 13-inch terrine mold with a layer of fatback. Fill the terrine with the meat mixture, lightly pressing down to ensure there are no air pockets. Place the bay leaves on top and cover with the caul fat if using, tucking the edges into the sides of the terrine.
Place the terrine in a large roasting pan and transfer to the oven. Carefully fill the roasting pan with water until it reaches halfway up the terrine. Bake, uncovered, for 2 hours.
Carefully remove the terrine from the water bath and cover with a lid or aluminum foil. Weight down the lid with weights or a foil-wrapped brick and let cool for about 1 hour. Remove the weights and lid and turn the pate out of the terrine. Refrigerate until ready to serve.
To serve, cut the pate into slices and serve with cornichons and crusty bread.
Caul fat is a thin membrane that surrounds the internal organs in some animals, such as cows, sheep and pigs. It is often used as a casing for sausages or roulades, or as a top layer for pates. It does not have much flavor, so its primary purpose is either to hold something together or to provide some fat/moisture as the food cooks. If you cannot find caul fat, you can make the terrine without it.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.