Breakfast Casserole

1 lb sausage
6 slices white bread
softened margarine
1 1/2 cup shredded longhorn cheese
5 eggs
2 cups half and half
1 teaspoon salt
1 teaspoon dry mustard

Cook sausage over medium flame until done, stirring to crumble well. Drain sausage on paper towels; set aside.
Spread each slice of bread with margarine; cut into cubes.
Place bread cubes in a 13x9x2 inch baking pan; sprinkle with sausage and top with cheese.
Combine remaining ingredients and pour over mixture in baking pan.
Chill at least 8 hours; remove from refrigerator.
Bake in 350 degree oven 40-50 minutes.