Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Peel the sweet potato and cut it into 1/2-inch cubes, then slice the chicken breast into bite-sized pieces.
Place the chicken, sweet potato cubes, broccoli florets, and sliced red bell pepper onto the prepared baking sheet.
Drizzle the extra virgin olive oil over the chicken and vegetables, ensuring everything is lightly coated.
Sprinkle the sea salt, black pepper, garlic powder, and dried oregano evenly over the ingredients on the pan.
Toss the mixture with your hands or a spatula to distribute the seasonings, then spread everything out into a single layer.
Roast in the oven for 20 to 25 minutes until the chicken is cooked through and the sweet potatoes are tender and golden.
Remove the pan from the oven and immediately drizzle with fresh lemon juice to brighten the flavors before serving.