Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper for easy cleanup.
Scrub the sweet potato thoroughly and cut it into 1-inch thick wedges or uniform cubes.
Place the sweet potato wedges and broccoli florets in a mixing bowl, tossing them with half of the olive oil and a small pinch of sea salt.
Pat the chicken breast dry with a paper towel, then rub it with the remaining olive oil, dried rosemary, garlic powder, sea salt, and black pepper.
Arrange the seasoned chicken and sweet potatoes in a single layer on the prepared baking sheet, ensuring they are not overcrowded.
Roast in the center of the oven for 15 minutes, then use tongs to flip the sweet potatoes and add the broccoli to the tray.
Continue roasting for another 10 to 12 minutes, or until the chicken reaches an internal temperature of 165°F and the potatoes are fork-tender.
Remove from the oven and let the chicken rest for 5 minutes before slicing to ensure the meat remains juicy.