3 tbsp. butter
2 tbsp. flour
1 tsp. salt
1/4 tsp. pepper
3 c. milk
3 1/2 - 4 c. thinly sliced potatoes (about 3 - 5 med.)
2 tbsp. minced onion

In 1 quart glass measuring cup, place butter and microwave at high 1/2 minute, or until melted. Blend in flour and seasonings. Gradually stir in milk. Microwave at high 8 to 10 minutes stirring every 3 minutes. Layer half of potatoes, onion and sauce in greased 3 quart casserole. Repeat layers. Cover with Saran Wrap. Microwave at high 17 to 19 minutes, stirring after 10 minutes. Remove from oven and let stand 5 minutes before serving.