Preheat oven to 400°. In a large skillet, cook beef over medium heat 10-12 minutes or until no longer pink, breaking into crumbles; drain. Add taco seasoning and prepare according to package directions. Spoon meat into a greased 13x9-in. baking dish., In a large bowl, beat eggs and milk. Stir in biscuit mix and pepper. Pour over meat. Bake, uncovered, 20-25 minutes or until golden brown. Cool 5-10 minutes., Spread sour cream over top; sprinkle with lettuce, tomato, green pepper, onions and cheese.