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