Preheat your oven to 425°F (220°C) and line a large rimmed baking sheet with parchment paper.
Pat the chicken breast completely dry with a paper towel to ensure the surface gets golden and crispy during roasting.
Dice the sweet potato into 1/2-inch cubes and place them on one side of the prepared baking sheet.
In a small bowl, whisk together the olive oil, sea salt, black pepper, oregano, garlic powder, and the zest from the half lemon.
Rub half of the oil-herb mixture thoroughly over the chicken breast and toss the remaining half with the sweet potato cubes.
Place the chicken on the baking sheet and roast for 15 minutes.
Add the broccoli florets to the pan, squeeze the juice from the half lemon over the chicken and vegetables, and roast for another 10-12 minutes until the chicken reaches an internal temperature of 165°F.
Remove from the oven and let the chicken rest for 5 minutes before slicing to keep it juicy.