Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Peel the sweet potato and carrots, then chop them into uniform 1-inch cubes to ensure even cooking.
Mince the garlic clove finely.
In a large mixing bowl, combine the chicken breast, chopped sweet potato, and carrots.
Add the olive oil, rosemary, thyme, sea salt, black pepper, and minced garlic to the bowl, tossing thoroughly until everything is well-coated.
Spread the chicken and vegetables onto the prepared baking sheet in a single layer, ensuring they are not overcrowded.
Roast in the oven for 25 to 30 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are fork-tender.
Remove from the oven and immediately drizzle with the fresh lemon juice to brighten the flavors before serving.