Preheat your oven to 425°F and line a large rimmed baking sheet with parchment paper for easy cleanup.
Pat the chicken breast completely dry with a paper towel to ensure the herb rub adheres and creates a beautiful crust.
In a small glass bowl, whisk together the olive oil, minced rosemary, thyme, garlic powder, sea salt, and black pepper.
Place the chicken and broccoli florets on the prepared baking sheet, then drizzle the herb oil mixture over everything, tossing the broccoli to coat.
Squeeze the juice of the half lemon over the chicken and place the squeezed lemon hull on the tray to infuse the air with citrus aroma.
Roast for 20 to 25 minutes until the chicken reaches an internal temperature of 165°F and the broccoli florets are tender with crispy, charred edges.
Remove from the oven and let the chicken rest for 5 minutes before slicing against the grain to maintain maximum juiciness.