Preheat your oven to 400°F and line a large sheet pan with parchment paper for easy cleanup.
Peel and cube the sweet potato into half-inch pieces, and slice the chicken breast into even, bite-sized strips.
Chop the broccoli into small florets and slice the red bell pepper into thin strips.
In a small mixing bowl, whisk together the extra virgin olive oil, fresh lemon juice, dried oregano, garlic powder, sea salt, and black pepper.
Place the chicken, sweet potatoes, broccoli, and bell peppers onto the prepared sheet pan.
Drizzle the lemon-herb marinade over the ingredients and toss thoroughly with your hands or tongs to ensure everything is well-coated.
Spread the mixture into a single, even layer across the pan to allow for proper roasting.
Bake for 20 to 25 minutes, or until the chicken is cooked through and the sweet potatoes are fork-tender and slightly caramelized.