Summer squash and red potatoes are vegetables that are in season now and make a delicious side dish to go with fish or steak.
1 large sweet onion, diced
8-10 small yellow summer squash (each about 4-inches long) sliced into thin rounds
5 medium red potatoes, peeled and sliced into thin rounds
3 cups shredded cheddar cheese
Salt and pepper
Preheat the oven to 400ºF
Coat the bottom of a large baking dish with olive oil. (I used a 12×8-inch oval baking dish.)
Cover the bottom of the dish with squash slices, overlapping them slightly. Sprinkle with salt and pepper. Sprinkle ⅓ of the onion and 1 cup of shredded cheese over the squash.
Cover the squash with potato slices, overlapping them slightly. Sprinkle with salt and pepper and then ⅓ of the onion and 1 cup of shredded cheese.
Cover the potatoes with another layer of squash, overlapping them slightly, Sprinkle with salt and pepper and then ⅓ of the onion and 1 cup of shredded cheese.
Spray a sheet of foil large enough to cover the baking dish with cooking spray. Place the sprayed side down on the baking dish and press tightly to the edges of the dish.
Bake the casserole for one hour. Remove the foil and bake for 30 minutes more. Let the casserole rest for 10 minutes before serving.