Preheat the oven to 400 degrees F. Spray a large tray with nonstick spray and set aside.
Whisk together the balsamic vinegar, garlic powder, and zesty Italian dressing dry packet.
Place 1/3 cup of the balsamic + Italian mixture in a large bag and add the chicken tenders. Coat and place in the fridge to marinate for at least 30 minutes and up to 6 hours.
Chop the broccoli and cauliflower into small pieces.In a bowl, toss broccoli, cauliflower, potatoes and carrots with Italian seasoning, olive oil, garlic powder, and add some seasoned salt and pepper to taste. Then place veggies on the prepared pan. Roast the veggies for 10-15 minutes.
Remove from the oven and flip around. Section the veggies to each side of the tray and place the chicken tenders in the center. Discard marinade that was used for the chicken. Brush the remaining 1/3 cup of the balsamic + Italian mixture over the chicken. Add the tomatoes.
Return to the oven and cook for another 7-15 minutes depending on the size of your chicken. Be careful to monitor the chicken so you don’t overcook it. Remember, the cooking time will largely vary based on the size of your chicken.
Serve the chicken and veggies with freshly chopped parsley, if desired.