Preheat your oven to 400°F and line a large baking sheet with parchment paper to prevent sticking without the need for added oils.
Place the cubed sweet potatoes on the baking sheet and season them with the garlic powder and a pinch of sea salt.
Roast the sweet potatoes for 15 minutes to ensure they become tender and slightly caramelized before adding the other components.
While the potatoes roast, rub the chicken breast thoroughly with the lemon zest, dried oregano, sea salt, and black pepper.
Remove the pan from the oven, move the potatoes to one side, and place the chicken breast and broccoli florets on the remaining space.
Drizzle the lemon juice over the chicken and broccoli to provide moisture and a bright, zesty flavor profile.
Return the pan to the oven and roast for an additional 18-20 minutes until the chicken reaches an internal temperature of 165°F.
Garnish the entire dish with freshly chopped parsley and serve immediately while hot.