Vegetarian Potato and Squash Casserole

Details

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