Sauteed Summer Squash with Bell Peppers and Onions is a delicious and colorful side dish that celebrates the flavors of summer. The combination of tender summer squash, sweet bell peppers, and caramelized onions creates a dish that is both savory and slightly sweet. This dish is quick and easy to make, making it perfect for a weeknight dinner or a backyard barbecue. Serve it alongside grilled meats or as a vegetarian main dish with some crusty bread.