Prepare the balsamic glaze: In a small saucepan, combine balsamic vinegar, olive oil, honey (if using), salt, and pepper. Bring to a simmer over medium heat.

Continue to simmer, stirring occasionally, for about 5-8 minutes, or until the glaze has thickened enough to coat the back of a spoon. Remove from heat and let cool. It will thicken further as it cools.

Assemble the salad: In a large bowl, gently combine the sliced peaches, mozzarella balls, arugula, and thinly sliced red onion.

Add the torn basil leaves to the salad mixture.

Drizzle about half of the cooled balsamic glaze over the salad and gently toss to coat. Add more glaze as desired.

Divide the salad among serving plates. Garnish with toasted pine nuts, if desired.