Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper for easy cleanup.
Peel and dice the sweet potato and carrots into uniform one-inch cubes to ensure they cook at the same rate.
Finely mince the garlic cloves and strip the leaves from the fresh rosemary and thyme sprigs, chopping them finely.
In a large mixing bowl, combine the chicken breast, diced vegetables, olive oil, minced garlic, and chopped herbs.
Season the mixture with sea salt and black pepper, tossing thoroughly to ensure every piece is well-coated.
Spread the chicken and vegetables in a single layer on the prepared baking sheet, leaving space between the items to allow for browning.
Roast for 25 to 30 minutes, or until the chicken reaches an internal temperature of 165°F and the root vegetables are tender and golden-brown.
Remove from the oven and let the chicken rest for 5 minutes before slicing to preserve the moisture.