1 med. onion, chopped
1 stick butter
8 oz. cream cheese or yogurt (plain)
1 can mushroom soup (10 3/4 oz.)
2 lbs. frozen hash brown potatoes
1 c. shredded sharp Cheddar cheese

Melt together onion, butter and cream cheese. Blend and add soup and potatoes. Layer potatoes and liquids in a 2 quart casserole and mix. Top with Cheddar cheese. Bake at 350 degrees for 1 1/4 hours. I cover with foil, removing for last 15 minutes.