Gather Ingredients

• 3 tablespoons unsalted butter
• 1 onion, chopped fine
• 1⁄2 cup (71 g) chopped red bell pepper, 1⁄2-inch (12-mm) pieces
• Salt and freshly ground black pepper
• 2 garlic cloves, minced
• 1 zucchini (8 ounces/225 g), cut into 1⁄2-inch (12-mm) pieces
• 1 yellow summer squash (8 ounces/225 g), cut into 1⁄2-inch (12-mm) pieces
• Kernels cut from 3 ears of corn
• Chopped fresh herbs (such as parsley, cilantro or basil)