In a large saucepan put sliced squash, onions, and peppers (seeded) and cover with enough water so it doesn't stick. Cover and boil until tender. Drain water. Place vegetables in a buttered large glass baking dish. Add salt and pepper. Spread soup over top. Sprinkle with cheese. Cover top with Ritz crackers crumbs. Bake at 375° till cheese bubbles (about 25 minutes)