Ingredients

• cooking spray
• 2 baking potatoes, cut into1/2-inch slices
• salt and ground black pepper to taste
• 3 large yellow summer squash, cut into 1/2-inch slices
• 4 large tomatoes, cut into 1/2-inch slices
• 1 sweet onion, cut into 1/4-inch slices
• 2 tablespoons butter

Instructions

1. Preheat oven to 375 degrees F (190 degrees C). Spray a 9x13-inch baking pan with cooking spray.
2. Cover the bottom of the baking pan with a layer of potato slices; season with salt and pepper. Place squash slices on top of the potatoes; repeat seasoning. Lay tomato slices on top of the squash; repeat seasoning. Continue layering the vegetables in this pattern, seasoning each casserole layer. Scatter onion over the casserole; dot with butter.
3. Bake in the preheated oven until the top is golden brown and the potatoes are soft, about 1 hour.