Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper.
Peel and dice the carrots, parsnips, and sweet potato into uniform 1-inch cubes for even roasting.
Finely mince the garlic, rosemary, and thyme, then whisk them into a small bowl with the olive oil, sea salt, and black pepper.
Place the chopped root vegetables in a bowl and toss with half of the herb-oil mixture until well coated.
Spread the vegetables in a single layer on the prepared baking sheet, leaving space in the center for the turkey.
Rub the turkey breast thoroughly with the remaining herb-oil mixture and place it in the center of the sheet pan.
Roast for 25 to 30 minutes, or until the turkey reaches an internal temperature of 165°F and the vegetables are tender.
Remove from the oven and let the turkey rest for 5 minutes before slicing to ensure it remains juicy.