Preheat your oven to 400°F (200°C).
In a small bowl, whisk together the Dijon mustard, olive oil, honey, garlic powder, onion powder, thyme, rosemary, salt, and pepper.
Place the chicken breasts in a large resealable bag or shallow dish. Pour the marinade over the chicken, ensuring it is well coated. Seal the bag or cover the dish and marinate in the refrigerator for at least 30 minutes, or up to 2 hours for more flavor.
While the chicken is marinating, prepare the vegetables. Chop your vegetables into uniform, bite-sized pieces. In a large bowl, toss the chopped vegetables with balsamic vinegar, salt, and pepper.
Spread the marinated chicken and the vegetables evenly on a large baking sheet.
Bake in the preheated oven for 25-30 minutes, or until the chicken is cooked through (internal temperature should reach 165°F) and the vegetables are tender.
Remove from the oven and let the chicken rest for 5 minutes before slicing. Serve the chicken alongside the roasted vegetables.