In bowl of an electric mixer combine 8 ounces of goat cheese and 3 egg yolks. Using a paddle, cream mixture, adding enough flour, a bit at a time, to make a tight but workable dough pliable enough to pipe from a pastry bag; season to taste with salt and pepper. Transfer dough to a pastry bag fitted with a 3/4-inch tip and pipe out long cylinders onto a wax or parchment paper-lined cookie sheet. Chill until firm. Cut each cylinder into 1-inch pieces. Lightly flour work surface and roll pieces, one at a time, over prongs of a fork, or over a gnocchi dowel. Chill again.
Preheat broiler. Lightly oil 2 individual gratin dishes or 1 medium baking dish. Cook sausage until browned, breaking it apart with a spoon. Drain off excess fat and keep warm. Bring a large pot of salted water to a boil and boil gnocchi, testing frequently for doneness. In a small bowl mix together remaining cheese and egg yolk. Slowly whisk in milk until thin enough to pour; season with salt and pepper. Drain gnocchi and toss with sausage. Transfer gnocchi to prepared dishes; spoon egg glaze over top. Broil until golden brown and bubbly. Serve directly from gratin dishes.
Yield: 2 to 3 servings