In small bowl, combine corn muffin mix, 2/3 cup milk and egg. Set aside. In medium skillet over medium heat, crumble and cook sausage until brown. Stir in corn, onions, peas and red pepper. Set aside. Press potatoes into a greased 9x 13 inch baking dish. Pour 1/3 cup milk over potatoes. Pour sausage mixture over potatoes and top with corn muffin mixture.
Cover and bake 45 minutes. Uncover and bake an additional 15 to 20 minutes or until top is golden brown.