Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper for easy cleanup.
Bring a medium pot of salted water to a boil and cook the whole wheat penne according to package directions until al dente, then drain and set aside.
Dice the chicken breast into one-inch cubes and chop the broccoli into small florets, the red onion into thin wedges, and leave the cherry tomatoes whole.
Spread the chicken, broccoli, onion, and tomatoes across the prepared baking sheet in a single layer.
Drizzle the olive oil over the chicken and vegetables, then sprinkle evenly with sea salt, black pepper, dried oregano, and garlic powder.
Toss everything with your hands or a spatula to ensure an even coating of oil and spices.
Roast in the oven for 15 to 18 minutes until the chicken is cooked through and the vegetables are tender with slightly charred edges.
Transfer the roasted chicken and vegetables into a large mixing bowl, add the cooked pasta, and toss well with the parmesan cheese before serving warm.