5 medium potatoes, peeled, chopped and cooked
2 medium diced onions
3 bell peppers, diced
¼ cup (1/2 stick) butter or margarine
¼ cup flour
1 ½ cups milk
1 (4-ounce) can mushroom pieces, drained
1 (4- to 6-ounce) jar pimentos, drained
½ cup grated cheese

Heat oven to 350 F. In a skillet, lightly sauté onions and pepper in butter. Add flour to mixture and stir to combine. Gradually add milk, stirring constantly. Add mushrooms and pimentos.
Lightly coat an 8-x10-inch baking dish with non-stick spray. Place potatoes in dish and top with prepared sauce. Sprinkle on cheese and bake 20 to 30 minutes until bubbly.