Apple And Sausage Pie

Name: Apple And Sausage Pie
Ingredients: 1 basic pie dough recipe, rolled out and lining a 9 or 10-inch pie dish, or 8x8 baking dish, chilled (or one frozen pie crust); 2 large tart Granny Smith apples, peeled and thinly sliced; 1/2 medium onion, chopped (about half a cup); 1 teaspoon sugar; 3 Tbsp butter; 3/4 lb sweet Italian sausage (bulk, or removed from casings); 1 clove garlic, minced; 2 cups shredded fontina, provalone, and or asiago cheese; 1 cup ricotta cheese; 1/4 cup feta cheese; 2 eggs, slightly beaten