Saute onion in butter 5 minutes or until tender Remove from heat Stir in sour cream and 12 cup cheese Set aside Combine cornmeal sugar and dill weed Stir well and set aside Combine next 5 ingredients stirring well Add all at once to cornmeal mixture stirring until blended Pour batter into a lightly greased 8-inch square pan Spread onion mixture evenly over top Sprinkle with remaining 12 cup cheese Bake at 400 for 25 to 30 minutes Yield 8 to 10 servings