Cook the penne pasta according to package instructions. Drain and set aside.
While the pasta cooks, season the chicken breasts with salt and pepper on both sides.
In a large skillet, heat olive oil over medium-high heat. Add the chicken breasts and cook for about 6-7 minutes on each side until golden brown and cooked through. Remove from the skillet and set aside to rest.
In the same skillet, add the diced onion and sauté for 3-4 minutes until translucent. Add the minced garlic and cook for an additional 1 minute.
Stir in the sun-dried tomatoes, chicken broth, heavy cream, dried basil, and dried oregano. Bring the mixture to a gentle simmer, stirring occasionally.
Add the grated Parmesan cheese to the skillet and stir until melted and the sauce becomes creamy.
Slice the cooked chicken into strips and add it back to the skillet. Combine the chicken with the sauce.
Add the cooked penne pasta to the skillet and toss everything together until well coated in the sauce.
Taste and adjust seasoning with salt and pepper, if needed.
Serve on plates and garnish with fresh basil leaves if desired.