Preheat grill to medium. If using wooden skewers, soak for at least 30 minutes.
Place tomatoes and diced peach in a medium bowl. Drizzle on olive oil and season with salt and pepper. Toss to lightly coat in oil.
Arrange tomatoes, peaches, and halloumi on skewers as desired.
Place on oiled grill until tomatoes are just charred, halloumi is lightly browned, and peaches are lightly browned, about 5-8 minutes. Drizzle on basil vinaigrette if desired and serve.