Preheat oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.
Dice the sweet potato into 1-inch cubes and halve the Brussels sprouts, ensuring they are uniform in size for even cooking.
Place the chicken breast, sweet potato cubes, and Brussels sprouts onto the prepared baking sheet.
Drizzle the extra virgin olive oil over the chicken and vegetables, then sprinkle with sea salt, black pepper, rosemary, thyme, and minced garlic.
Toss all ingredients together with your hands or tongs until everything is thoroughly coated in oil and spices.
Arrange the ingredients in a single layer, ensuring the chicken has space and isn't crowded by the vegetables.
Roast in the center of the oven for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the vegetables are fork-tender.
Let the chicken rest for 5 minutes before slicing to keep it juicy, then serve alongside the roasted root vegetables.