Bring a large pot of salted water to a boil. Cook the penne pasta until al dente, about 8–10 minutes. Drain and set aside.

Heat olive oil in a skillet. Season diced chicken with salt and pepper, sauté until browned, about 5–7 minutes. Remove chicken from skillet.

In the same skillet, sauté minced garlic until fragrant, about 30 seconds. Add marinara sauce and dried oregano. Simmer for about 5 minutes.

Return chicken to skillet and stir in the drained pasta until well-coated.

Preheat oven to 350°F. Transfer the mixture to a greased baking dish. Top with mozzarella and Parmesan cheeses. Bake for 20–25 minutes until cheese is bubbly.

Let cool for 5 minutes. Optionally, garnish with fresh basil before serving.