My sister, Beth, was always the squash eater in our family. Just the thought of the yellow stringy stuff could send me from the table. This is the recipe that changed it all for me. I have Garth to thank because he loves squash casserole, so I went in search of a recipe. Beth shared this one with me (of course). I tasted it just to be nice, and never looked back. I am now officially a squash eater!
Preheat the oven to 350°F. Butter a 2-quart casserole dish.
Place the sliced squash and the onion in a medium saucepan with about a cup of water and ½ teaspoon of the salt. Cover and cook over medium until the squash is tender, about 15 minutes. Drain and cool.
Put the squash into a bowl and beat with an electric mixer; the mixture should remain kind of chunky. Add the egg, mayonnaise, cheese, remaining ½ teaspoon salt, and the pepper and mix until combined. Pour the squash mixture into the prepared dish, top with the crumbs, and bake for 30 minutes.
The natural moisture content of a squash varies with the variety and with growing conditions. Choose a yellow straight or crookneck summer squash, and drain the cooked squash thoroughly before combining it with the other ingredients.