In a large skillet, cook sausage until no longer pink; drain. Place in a greased 13x9-in. baking dish. Layer with cheeses, onion, chilies and jalapeno if desired. In a bowl, beat eggs and seasonings. Pour over cheese., Bake, uncovered, at 375degrees for 18-22 minutes or until a knife inserted in the center comes out clean. Cool for 10 minutes; cut into 1-in. squares.