3 tablespoons butter

2 tablespoons flour

1 teaspoon dry mustard

1 teaspoon salt

1/4 teaspoon pepper

1 cup half and half

1 20-ounce package frozen whole onions (small) thawed and drained well

2 9-ounce packages frozen french style green beans, thawed and drained well

12 slices american cheese

1/2 cup chopped walnuts

Melt butter in  a saucepan. Stir in flour, mustard, salt, and pepper. Cook and stir over low heat untl mixture is bubbly. Slowly stir in half and half. Stir in vegetables. Place 1/3 of the mixture in an 8-inch square baking dish. Top with 4 slices of cheese. Top with nuts and bake at 350 degrees for 35 minutes. Can be prepared the day before and refrigerated. If refrigerated, bake at 350 degrees for 45 minutes.