Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper for easy cleanup.
Dice the sweet potato into half-inch cubes and chop the red bell pepper into bite-sized pieces.
Cut the chicken breast into even 1-inch chunks to ensure they cook at the same rate as the vegetables.
In a small bowl, whisk together the extra virgin olive oil, lemon juice, dried oregano, garlic powder, sea salt, and black pepper.
Place the chicken chunks, sweet potato cubes, broccoli florets, and bell peppers on the prepared sheet pan.
Pour the lemon-herb dressing over the ingredients and toss thoroughly with your hands or tongs to coat every piece.
Spread the mixture into a single layer, ensuring the pan is not overcrowded so the vegetables roast rather than steam.
Bake for 20 to 25 minutes, or until the chicken is cooked through and the sweet potatoes are fork-tender.
Let the meal cool slightly before portioning into airtight containers for your weekly meal prep.