Heat a grill over medium heat. Alternatively, you can use an inside stovetop griddle. Add the watermelon and peach slices to the grill (or griddle) and grill for about 10 minutes, flipping halfway through.
Meanwhile, add the arugula to a medium bowl and toss with all the balsamic dressing ingredients. Once the fruit is grilled, add to the bowl, or plate and top with hemp seeds.