4 tbsp. butter
2 tbsp. all-purpose flour
1 tsp. salt
1/4 tsp. pepper
2 c. milk
3 med. size potatoes (1 lb.), cut into 1/8" thick rounds
1 med. size onion, chopped fine (opt.)

Place butter in 1 1/2 quart measure or bowl. Microwave on High 30 to 45 seconds until melted. Stir in flour, salt and pepper until blended. Gradually whisk in milk until smooth. Microwave on High 8 to 10 minutes, stirring twice until boiling and slightly thickened.

Lightly grease a 2 quart casserole. Arrange half the potatoes in bottom, sprinkle with half the onion, pour half white sauce on top. Repeat layers, cover with vented plastic wrap. Microwave on High 16 to 18 minutes, rotating dish 1/2 turn once until potatoes are tender. Let stand 5 minutes. Sprinkle with parsley.