Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Wash and dice the Yukon Gold potato into 1/2-inch cubes to ensure they roast evenly and get crispy.
In a small bowl, whisk together the extra virgin olive oil, lemon juice, lemon zest, minced fresh rosemary, garlic powder, sea salt, and black pepper.
Place the chicken breast and diced potatoes on the sheet pan, then drizzle with half of the lemon-herb oil mixture, tossing well to coat.
Spread the chicken and potatoes in a single layer and roast in the oven for 15 minutes.
Remove the pan from the oven, add the broccoli florets, and drizzle with the remaining oil mixture.
Return the pan to the oven and roast for another 10-15 minutes, or until the chicken reaches an internal temperature of 165°F and the potatoes are golden brown.
Let the chicken rest for 5 minutes before slicing and serving alongside the roasted vegetables.