Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Peel the sweet potato and dice it into 1/2-inch cubes, and cut the broccoli into bite-sized florets.
In a small mixing bowl, whisk together the olive oil, minced garlic, dried rosemary, dried thyme, sea salt, and black pepper.
Place the chicken breast, diced sweet potatoes, and broccoli florets onto the prepared baking sheet.
Drizzle the garlic-herb oil mixture over the chicken and vegetables, tossing thoroughly to ensure everything is evenly coated.
Spread the ingredients out into a single layer, making sure the chicken has enough space to roast properly without steaming.
Roast in the oven for 20-25 minutes, or until the chicken reaches an internal temperature of 165°F and the sweet potatoes are tender when pierced with a fork.
Remove from the oven and let the chicken rest for 5 minutes before slicing and serving alongside the roasted vegetables.