Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.
Peel and dice the sweet potato into half-inch cubes and slice the carrots into half-inch rounds to ensure even cooking.
Mince the garlic cloves and finely chop the fresh rosemary leaves.
Place the chicken breast, sweet potato cubes, and sliced carrots onto the prepared baking sheet.
Drizzle the olive oil over the chicken and vegetables, then sprinkle with the minced garlic, chopped rosemary, sea salt, and black pepper.
Toss everything thoroughly with your hands or tongs to ensure every piece is well-coated in the herb oil.
Spread the ingredients out into a single layer, making sure the chicken breast has enough space around it.
Roast in the center of the oven for 25 to 30 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are tender and golden.
Remove from the oven and let the chicken rest for 5 minutes before slicing to keep it juicy and flavorful.