Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Cut the chicken breast into 1-inch bite-sized pieces and chop the broccoli, bell pepper, and zucchini into uniform sizes to ensure even cooking.
Place the chicken and vegetables on the prepared baking sheet in a single layer.
Drizzle the olive oil over the chicken and vegetables, then sprinkle with dried oregano, garlic powder, sea salt, and black pepper.
Toss everything together with your hands or a spatula until the ingredients are thoroughly and evenly coated with oil and seasonings.
Roast in the oven for 18-22 minutes, or until the chicken is cooked through and the vegetables are tender with slightly charred edges.
Divide the cooked quinoa into your meal prep containers and top with the roasted chicken and vegetable mixture.
Squeeze fresh lemon juice over each bowl before sealing the lids to brighten the flavors and keep the chicken moist.