2) Cook beef and onion till the meats color lightens.
3) With a fork blend flour, salt, and pepper.
4) Stir in milk and stirring constantly cook till thick.
5) Mix 1 1/2 cups cheese and cook till melted.
6) Add to cooked macaroni and beans. Transfer to 2-quart casserole.
7) Sprinkle 1/2 cup cheese on top.
8) Bake in oven for 35 minutes till top is lightly browned.