Southern Squash Casserole Recipe Type: Side Dish Cuisine: American Ingredients 3 lb yellow squash, sliced or diced 1/2 c diced Vidalia onion, optional 1 can(s) cream of mushroom or chicken soup, 10.5 oz. 1 c mayonaise 1 egg 8 oz shredded cheddar cheese (sharp is my favorite) 1 tsp salt 1/2 tsp fresh ground black