4 tbsp. butter
1/3 c. onion, chopped
1 tsp. salt
1/8 tsp. pepper
1 1/2 tbsp. flour
2 1/4 c. milk
6-8 med. potatoes, peeled and sliced

Melt butter in a saucepan. Add chopped onions and cook over low to medium heat for 2-3 minutes. Add salt, pepper and flour. Mix well. Will be lumpy and thick. Add milk. Cook over medium-high heat stirring almost constantly until mixture is boiling. Stir while boiling for 2 minutes. Mixture will have thickened.

Pour mixture over prepared potatoes in a 6 quart glass casserole dish. Microwave for 12 minutes with cover on. Mix well and microwave for another 12-13 minutes. Let stand for 5 minutes before serving.