Squash Casserole

1 pound squash

2 onions, sliced

1 tsp sugar

1 egg

salt and pepper

½ stick butter

¼ cup milk

1 cup bread crumbs

1 cup grated cheese

Cook squash and onions in salted water until tender.  Drain.  Beat until light, add remaining ingredients reserving 1/3 of cheese and bread crumbs for top.  Pour into buttered casserole dish.  Sprinkle reserved cheese and bread crumbs over top.  Bake at 350 degrees until lightly browned.