3/4 c. milk
1 can (10 oz.) cream of mushroom soup
4 med. potatoes, sliced 1/8 inch thick
1 c. Cheddar cheese, grated or shredded
1/2 small onion, chopped

Combine milk and soup in microwave safe, 2 quart casserole bowl. Stir in remaining ingredients. Cover and microwave on high 10 minutes. Stir. Microwave another 12 to 15 minutes or until potatoes are tender.