Rinse chicken breasts in cold water. Layer between sheets of wax paper and pound to even thickness. Season both sides with Montreal Steak seasoning.
Preheat grill for medium high heat, lightly oil grate and grill chicken breasts on medium high heat for 6-8 minutes on each side. (For Skillet method: Heat 2 tablespoons butter and 2 tablespoons olive oil in a large skillet over medium heat. Once the butter and olive oil begins to sizzle, add chicken breasts and cook about 5 minutes each side.) Set chicken aside to cool.
Fill a large large pot with water and salt to taste. Add penne pasta noodles and cook according to package directions.
Heat the 2 tablespoons butter and 2 tablespoons olive oil in the skillet over medium heat. Add the garlic and onion; cook, stirring occasionally, until tender about 5 minutes. Add the chicken broth to the pan and allow to reduce by half.
Meanwhile, slice chicken; set aside. Once the broth has reduced, stir in tomato sauce. Add the heavy cream and stir well to combine. Season with salt and pepper to taste. Turn heat to low. Chop the parsley and basil, add to sauce and mix well. Drain pasta and add to sauce. Stir well to coat. Serve pasta on plates, top with sliced chicken. If desired, top with Parmesan cheese.