Bring a large pot of salted water to a boil. Add the 12 oz penne pasta and cook until al dente, about 10 to 12 minutes. Drain and set aside, reserving about ½ cup of pasta water.
Heat 2 tablespoons of olive oil in a large skillet over medium-high heat. Add the diced chicken breast, season with salt, pepper, and 1 teaspoon of Italian seasoning. Cook for 5-7 minutes until cooked through and slightly golden. Remove chicken and set aside.
Reduce heat to medium and add the minced garlic to the same skillet. Sauté for 30-60 seconds until fragrant, being careful not to burn it.
Pour in 1 cup chicken broth and 1 cup heavy cream. Stir and bring to a gentle simmer. Cook for 3-4 minutes to thicken slightly.
Gradually add 1 cup grated Parmesan cheese to the sauce, stirring constantly until melted and smooth. Add reserved pasta water if sauce is too thick.
Return cooked chicken to the skillet and toss to coat in the sauce. Add drained penne pasta and mix gently until combined and heated through.
Remove from heat and sprinkle with freshly chopped parsley. Serve immediately while warm.