I can vividly recall the first time I ever made a summer squash casserole.  I was perplexed. Mix up mayonnaise, sour cream, and an egg, add fresh corn and chopped onion, layer between slices of yellow squash, and top with sharp cheddar and buttered Ritz Cracker crumbs. Bake. I mean. Whoa. It just seemed like tooooo muuuuch stuff. But once baked, sure enough, all the ingredients did work and come together, and it hit all the right notes.