1.5kg mixed bell peppers and chiles (any more than 2 hot chiles and the peppers will end up spicy, which is delicious as long as that is what you are going for), large peppers seeded, cut off of cores into quarters
6 garlic cloves, lightly crushed
⅓ cup Saint George Extra Virgin Olive Oil
Kosher salt, freshly ground pepper
300ml fresh mozzarella
Basil leaves (for serving)
1Tbsp. white balsamic vinegar
Preheat oven to 325°. Toss peppers, chiles, garlic, and oil in a Dutch oven or heavy roasting pan; season with salt and pepper and toss again to coat. Cover and roast, tossing occasionally, until peppers are very tender, 2–2½ hours. Let cool.
Arrange half of peppers on a platter. Top peppers with mozzarella and basil. Measure out 3 Tbsp. of the oily juices left behind and transfer to a small bowl (save remaining peppers and their juices for another use; we love them tossed with pasta, layered into sandwiches, or stirred into frittatas). Add vinegar; season with salt. Stir to combine, then drizzle dressing over salad.
Do Ahead: Peppers can be roasted 1 week ahead. Cover and chill.