Corn Bread Zucchini Bake Casserole

2.00 medium zucchini
0.50 pound bulk italian or pork sausage
0.25 cup chopped onion
1.00 packet (8 or 8 1/2 ounce) corn muffin mix
0.50 cup shredded cheddar cheese

Coarsely shred enough zucchini to make 1/3 cup, set aside. Cut remaining zucchini into 1/4 inch slices. In a 10 inch skillet brown sausage. Remove sausage from skillet, reserve drippings. To drippings in skillet, add zucchini slices and onion, stir to coat. Cover and cook over medium-low heat about 5 minutes. In a greased 8 x 1-1/2 inch round baking dish starting in center arrange cooked zucchini slices in concentric circles using all sides. Prepare corn muffin mix to package directions. Stir in shredded zucchini, cooked sausage and cheese. Spread mixture over zucchini slices in pan. Bake 350 degrees for 25 to 30 minutes. Using a spatula loosen side, invert dish. Cut into wedges to serve.