Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Cut the chicken breast into 1-inch bite-sized cubes.
In a small mixing bowl, combine the ground turkey with half of the oregano, garlic powder, salt, and pepper, then roll into small 1-inch meatballs.
Place the chicken cubes, turkey meatballs, broccoli florets, and sliced bell peppers onto the prepared baking sheet in a single layer.
Drizzle the olive oil and lemon juice over the protein and vegetables, then sprinkle with the remaining oregano, garlic powder, salt, and pepper.
Toss everything gently on the pan to ensure even coating, then spread it back out so nothing is crowded.
Roast for 18 to 22 minutes, or until the chicken is cooked through and the turkey meatballs reach an internal temperature of 165°F.
Remove from the oven and let cool slightly before dividing into meal prep containers.