From Stevie’s files, circa 1981
5-8 sliced buttered wheat bread, cut in cubes
3/4 lb grated cheddar cheese
4 eggs, lightly beaten
2 C milk
1/2 T salt and pepper
1/2 T dry mustard
2 small onions, finely chopped and sauteed in butter
Alternate layers off bread and cheese in greased casserole. Combine other ingredients and pour them over the top. Let sit to soak in.
Bake 1 hour at 350 F.