Special Broccoli-Potato Supreme Casserole

SPECIAL BROCCOLI POTATO SUPREME CASSEROLE3 c. hot mashed potatoes (store bought or homemade)4 oz. cream cheese, soft¼ c. milk1 large egg2 T. butter, softSalt, black pepper1 (2.8-oz.) can French-fried onions, divided5 c. fresh broccoli florets1 c. shredded cheddar cheese In…