Calico Ham Casserole
["1/2 c. butter or margarine", "1 medium onion, chopped", "1/2 c. flour", "1/2 tsp. dry mustard (optional)", "3 c. milk", "1/2 tsp. salt", "1/2 lb. Cheddar cheese, shredded", "3 c. cubed, cooked ham (turkey ham can be used)", "1 (16 oz.) pkg. frozen mixed vegetables, thawed", "1/4 c. butter, melted and mixed with 1 1/2 c. fresh bread cubes"]
["Melt the 1/2 cup butter in large pan over moderate heat.", "Add onion.", "Cook until onion is soft.", "Add flour and mustard.", "Cook over moderate heat, stirring occasionally.", "Gradually add milk. Cook, stirring frequently, until mixture thickens.", "Add salt and cheese.", "Cook, stirring, until cheese melts.", "Fold in ham and uncooked vegetables.", "Spoon into 9 x 13-inch baking dish.", "Cool mixture, slightly at room temperature, then refrigerate, covered, overnight, allowing flavors to blend.", "Let stand at room temperature 45 minutes before baking.", "Sprinkle top with bread cubes and bake 40 minutes at 350\u00b0.", "Serves 8 to 10."]
["butter", "onion", "flour", "dry mustard", "milk", "salt", "Cheddar cheese", "frozen mixed vegetables", "butter"]