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 chop the broccoli into bite-sized florets.
Slice the chicken breast into even 1-inch strips or bite-sized pieces to ensure they cook at the same rate as the vegetables.
In a large mixing bowl, whisk together the extra virgin olive oil, lemon juice, lemon zest, dried oregano, garlic powder, sea salt, and black pepper.
Add the chicken, sweet potato cubes, and broccoli florets to the bowl and toss thoroughly until every piece is coated in the herb marinade.
Spread the mixture onto the prepared sheet pan in a single layer, ensuring nothing is overcrowded so the vegetables roast rather than steam.
Roast in the center of the oven for 20 to 25 minutes, or until the chicken is cooked through and the sweet potatoes are fork-tender.
Remove from the oven and let cool slightly before dividing into meal prep containers for the week.