Cheesy Apple and Sausage Pie

Name: Cheesy Apple and Sausage Pie
Ingredients: 1 basic pie dough recipe , rolled out and lining a 9- or 10-inch pie dish, or 8x8-inch baking dish, chilled (or 1 frozen pie crust ); 2 large tart green apples , peeled and sliced 1/4-inch thick; 1/2 medium onion , chopped (about 1/2 a cup); 1 teaspoon sugar; 3 tablespoons butter; 3/4 pound sweet italian sausage (bulk or removed from casings); 1 clove garlic , minced; 2 cups ( 8 ounces ) shredded fontina , provolone, and or Asiago cheese; 1 cup ricotta cheese; 1/4 cup feta cheese; 2 eggs , slightly beaten