Preheat oven to 375°. In a large skillet, cook sausage over medium heat until no longer pink; drain. Spoon into a greased 13x9-in. baking dish. Layer with spinach, bacon, onion, red pepper and cheeses., In a large bowl, whisk eggs, milk and seasonings; pour over top. Bake 30-35 minutes or until a knife inserted in the center comes out clean. Let stand 5 minutes before cutting.