Preheat your oven to 400°F and line a large baking sheet with parchment paper for easy cleanup.
Peel and chop the sweet potato and carrots into uniform 1-inch cubes to ensure even roasting.
Mince the garlic cloves finely and set aside.
In a large mixing bowl, toss the cubed sweet potato and carrots with half of the olive oil, half of the sea salt, and half of the black pepper.
Pat the chicken breast dry with a paper towel, then rub both sides with the remaining olive oil, minced garlic, dried rosemary, dried thyme, and the rest of the salt and pepper.
Spread the seasoned vegetables in a single layer on the prepared baking sheet, leaving space in the center for the chicken.
Place the chicken breast in the center of the sheet and roast for 25 to 30 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender and caramelized.
Let the chicken rest for 5 minutes before slicing to keep it juicy, then serve alongside the roasted root vegetables.