Sausage and Ham Breakfast Casserole (also known as 24-Hour Omelet)

6-7 slices of bread, crustless and cubed
1 lb. chopped ham (or sausage, browned and drained — or 1/2 of BOTH)
1 c. grated cheddar cheese
6 beaten eggs
2 c. milk
1/2 tsp. dry mustard
1/2 tsp. salt
1/4 c. butter
Mix all ingredients except butter. Pour in 9×12 pan. Melt butter and drizzle over the top. Cover and refrigerate overnight (or at least 6 hours). Bake uncovered at 325 for 1 hour.