Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Peel the sweet potato and cut it into 1-inch cubes; peel the carrots and slice them into 1/2-inch thick rounds.
Place the chicken breast, cubed sweet potatoes, and sliced carrots onto the prepared baking sheet.
Drizzle the olive oil over the chicken and vegetables, then sprinkle evenly with the sea salt, black pepper, dried rosemary, and garlic powder.
Use your hands or tongs to toss the vegetables and coat the chicken thoroughly so every piece is well-seasoned.
Spread everything out into a single layer, ensuring the chicken has space around it to roast properly.
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, then serve alongside the roasted roots.