Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Peel the sweet potato and cut it into 1-inch cubes, and chop the broccoli into bite-sized florets.
Mince the garlic cloves and finely chop the fresh rosemary and thyme leaves.
In a small bowl, whisk together the olive oil, minced garlic, rosemary, thyme, sea salt, and black pepper.
Place the chicken breast on one side of the baking sheet and rub it with half of the garlic-herb oil mixture.
Toss the sweet potato cubes in the remaining oil mixture and spread them in a single layer on the other side of the baking sheet.
Roast for 15 minutes, then remove the pan from the oven and add the broccoli florets to the tray.
Return the pan to the oven and roast for an additional 12-15 minutes until the chicken reaches an internal temperature of 165°F and the vegetables are golden and tender.