Preheat your oven to 400°F (200°C).
Peel the sweet potato and cut it into 1/2-inch cubes.
In a small bowl, mince the garlic and combine it with the dried rosemary, dried thyme, sea salt, and black pepper.
On a large parchment-lined baking sheet, toss the sweet potato cubes with 0.5 tbsp of olive oil and a pinch of the herb mixture.
Roast the sweet potatoes for 10 minutes.
While potatoes roast, rub the chicken breast with the remaining 0.5 tbsp of olive oil and the rest of the garlic-herb mixture.
Remove the baking sheet from the oven, move the potatoes to one side, and place the chicken breast on the other side.
Return the pan to the oven and roast for 15-20 minutes, or until the chicken reaches an internal temperature of 165°F.
While the chicken and potatoes finish roasting, steam the broccoli florets over boiling water for 5 minutes until tender-crisp.
Serve the roasted chicken alongside the sweet potatoes and steamed broccoli.