Scrub and slice 6-8 medium sized summer yellow crook-neck squash. Add 1 medium diced onion and simmer until tender. Drain most of liquid and mash. Add 3-4 tablespoons of butter, 1 beaten egg, another tablespoon grated onion, crumbs from a couple slices of bread (freeze bread heels and grate them while frozen), about 2 teaspoons sugar, and salt and pepper to taste. Put into buttered casserole dish and grate another slice of bread on top; dot with butter. Bake at 350 degrees for 30 minutes.