Slice peaches into 6 segments per peach. In a small bowl, toss with drizzles of olive oil and balsamic and just a small pinch of salt.

Heat your grill (or grill pan) to medium high heat and brush it with some oil. Place the peach slices on the hot grill and cook each side for 2-3 minutes without moving them (near the end you can gently peek to see how your grill marks are coming along).

When your peaches are grilled, set aside and allow them to cool to room temperature.

Meanwhile, make the pesto: Combine the mint and basil, pine nuts, garlic, lemon juice and zest, and olive oil in a small food processor with pinches of red pepper flakes, salt, and pepper. Pulse to combine, adding more oil for a smoother pesto, or leaving it chunky – whichever consistency you prefer.

Assemble crostini: Top the toasted bread with the arugula, fresh mozzarella, if using, a dollop of pesto, and a peach slice.