Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Peel the sweet potato and cut it into 1/2-inch cubes, and chop the broccoli into bite-sized florets.
In a small mixing bowl, whisk together the olive oil, lemon zest, lemon juice, minced garlic, chopped rosemary, and chopped thyme.
Place the chicken breast on one side of the baking sheet and spread the sweet potatoes and broccoli on the remaining space.
Drizzle the lemon-herb oil mixture over the chicken and vegetables, ensuring everything is evenly coated.
Sprinkle the sea salt and black pepper over the entire tray.
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 it against the grain to serve with the roasted vegetables.