2 1/2 c. water
1 (5.5 oz.) pkg. au gratin potatoes
2/3 c. milk
2 tbsp. butter
1 (4 oz.) can mushrooms, drained
1 or 2 med. tomatoes, chopped
1/2 c. croutons, crushed

Cover and microwave water to boiling in 3 quart casserole on high, 6 to 7 minutes. Stir in potato slices, sauce mix, milk, butter and mushrooms. Cover and microwave until tender, 15 to 20 minutes. Stir in tomato; top with croutons. 9 servings.