Heat chicken. Meanwhile, combine balsamic vinegar, dijon mustard, honey, garlic powder, and onion powder in a small saucepan and season with Kosher salt. Bring to a simmer over medium heat and cook for about 3-5 minutes, until mixture has thickened slightly. Brush chicken on both sides with balsamic glaze, and top with cherry tomatoes, mozzarella, and basil.