Preheat your oven to 400°F (200°C) and line a large rimmed sheet pan with parchment paper for easy cleanup.
Peel the sweet potato and cut it into 1/2-inch cubes, slice the zucchini into half-moons, and break the broccoli into bite-sized florets.
Place the chicken breast on one side of the prepared sheet pan and arrange the sweet potatoes, zucchini, and broccoli on the other side.
In a small glass bowl, whisk together the extra virgin olive oil, minced garlic, dried rosemary, dried thyme, sea salt, and black pepper.
Drizzle the herb-oil mixture over both the chicken and the vegetables, using your hands or a brush to ensure the chicken is fully coated and the vegetables are tossed evenly.
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 immediately drizzle the fresh lemon juice over the chicken and vegetables to brighten the roasted flavors before serving.