Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper for easy cleanup.
Peel the sweet potato and cut it into uniform 1/2-inch cubes to ensure even roasting.
Trim the woody ends off the asparagus spears and finely mince the fresh garlic and rosemary.
Place the chicken breast, cubed sweet potatoes, asparagus, and cherry tomatoes in a single layer on the prepared baking sheet.
Drizzle the olive oil over the chicken and vegetables, then sprinkle evenly with the minced garlic, rosemary, sea salt, and black pepper.
Toss the vegetables gently to coat them in the oil and seasonings, and turn the chicken to ensure both sides are flavored.
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 sweet potatoes are fork-tender.
Remove from the oven and let the chicken rest for 5 minutes before slicing to ensure the juices remain locked inside.