Begin by bringing a large pot of salted water to a rolling boil over high heat. Add the penne pasta and cook according to package instructions until al dente, usually 8-10 minutes. Once cooked, drain the pasta in a colander, reserving half a cup of the starchy pasta water for later. Set the pasta aside.

In a large skillet, heat 2 tablespoons of olive oil over medium-high heat. Once hot, add the seasoned chicken breast pieces to the pan. Cook for about 5-7 minutes, or until the chicken is golden brown and no longer pink in the center. Remove the cooked chicken from the skillet and set it aside.

Using the same skillet, reduce the heat to medium and add 2 tablespoons of butter. Once melted, toss in some diced onions, bell peppers, and a sprinkle of garlic powder. Sauté the vegetables for 5-7 minutes, stirring occasionally, until they soften and become fragrant.

Pour in 1 cup of heavy cream and ½ cup of chicken broth into the pan, mixing well with the sautéed vegetables. Bring to a gentle simmer, then stir in ½ cup of grated Parmesan cheese and red pepper flakes if desired. Allow the sauce to thicken slightly for about 3-5 minutes.

Add the sautéed chicken and the cooked pasta into the creamy sauce, tossing everything together gently until each piece is well-coated. If the sauce is too thick, gradually pour in the reserved pasta water.

Once everything is combined and heated through, remove the skillet from the heat. Garnish with freshly chopped parsley or green onions and serve immediately while warm.