Begin by bringing a large pot of salted water to a boil over high heat. Once boiling, add your uncooked pasta and cook until al dente, reducing the package time by 2-3 minutes. Drain the pasta thoroughly and set aside.

In a large skillet, melt 2 tablespoons of butter over medium heat. Add cubed chicken breasts, seasoning with salt and pepper. Sauté the chicken for 5-7 minutes until golden brown and cooked through.

Add in the chopped onion, minced garlic, and diced red bell pepper to the skillet. Stir and cook for about 3 minutes until the onion is translucent and peppers soften.

Mix in the cream of chicken soup, milk, and chicken stock into the skillet. Whisk until smooth. Add in the cream cheese, stirring until melted and combined.

Sprinkle in the grated Parmesan cheese and dry Italian dressing mix. Stir thoroughly to ensure the mixture thickens slightly.

Gently fold in the reserved pasta, ensuring each piece is coated in the creamy sauce. Heat for an additional 2-3 minutes on low.

Preheat oven to 350°F (175°C). Transfer the mixture to a greased 9x13-inch casserole dish, spread evenly, top with remaining Parmesan, and bake for 30-40 minutes until golden brown.