Slice the mozzarella into 1/2-inch thick pieces. Start by cutting the ball into quarters, then slice each quarter crosswise into even slabs.

Halve the peaches, remove the pits, and cut each half into 4 wedges. Depending on size, cut the wedges into halves or thirds to create bite-sized chunks about 1 inch across.

Core the heirloom tomatoes, then halve them. Cut each half into 4 wedges, and slice those wedges into halves or thirds to match the peach pieces in size.

Tear the basil leaves into smaller pieces or give them a rough chop.

In a large salad bowl, combine the mozzarella, peaches, tomatoes, and basil. Drizzle with olive oil, season with salt and pepper, and toss gently until everything is evenly coated.

Drizzle the balsamic reduction over the top, if using, and serve right away.