Peel, slice and boil carrots until tender.
Melt butter in pan and sautÚ onion.
Mix-flour, pepper, salt, mustard, and celery salt.
Add to onion and butter mixture.
Add 2 c. milk and cook until thick.
Slice 1/2 ob. processed cheese.
Put layer of carrots in greased casserole, then layer of cheese, then carrots and cheese again.
Pour sauce over it.
Melt 3 tbsp. butter. Soak bread pieces in butter and sprinkle over top.
Bake uncovered at 350║ for 25 minutes.