Preheat your oven to 425°F (220°C) and line a sheet pan with parchment paper.
Slice the sweet potato into 1/2-inch rounds or cubes and place them on one side of the sheet pan. Drizzle with half the olive oil and season with a pinch of salt and pepper.
Cut the chicken breast into evenly sized pieces if desired or leave whole. Place on the sheet pan alongside the vegetables.
In a small bowl, mix the lemon juice, remaining olive oil, garlic powder, salt, and pepper to create a light marinade.
Drizzle the marinade evenly over the chicken and sweet potatoes.
Toss the broccoli florets with a small drizzle of olive oil, salt, and pepper, then add them to the sheet pan ensuring they are in a single layer for even crisping.
Roast the ingredients in the oven for about 20-25 minutes, or until the chicken is cooked through (internal temperature of 165°F), the sweet potatoes are tender, and the broccoli edges are crispy.
Remove from oven and let rest for a couple minutes before serving.