Bring a large pot of salted water to a boil. Add the penne pasta and cook according to package instructions until al dente. Drain and set aside.

While the pasta is cooking, heat 1/2 tablespoon of olive oil in a large pan over medium-high heat. Season the chicken breasts with salt and pepper, then cook for 5-7 minutes on each side until golden and fully cooked. Remove the chicken from the pan, allow to rest, and then slice into strips.

In the same pan, add the remaining olive oil and sauté the chopped onion until translucent. Add minced garlic and cook for another 1 minute.

Pour in the diced tomatoes, and stir in the dried basil and oregano. Allow the sauce to simmer for about 10 minutes so the flavors meld.

Reduce the heat and stir in the heavy cream, then add the sliced chicken to the sauce. Let everything heat through for 2-3 minutes.

Finally, combine the pasta with the sauce and chicken. Toss gently to coat, adjust seasoning with salt and pepper to taste, and serve immediately.