Prepare the Cajun Seasoning :In a small bowl, mix together all the dried spices—smoked paprika, oregano, thyme, garlic powder, onion powder, cayenne, black pepper, and salt. Set aside this flavorful blend to coat the chicken.
Season the Chicken : Place the cubed chicken breast into a medium bowl. Sprinkle the Cajun seasoning over the chicken and toss well to ensure every piece is evenly coated with the spices.
Sear the Chicken : Heat the olive oil and butter in a large, deep skillet over medium-high heat. When the butter is melted and bubbling, add the seasoned chicken pieces. Cook the chicken just long enough to develop a golden brown crust on each side—about 2-3 minutes per side—but don’t worry if it’s not fully cooked through yet.
Sauté the Onion: Add the diced onion to the skillet with the chicken. Stir and cook for 2-3 minutes until the onion softens and becomes translucent. The moisture from the onion will help lift any flavorful browned bits stuck to the pan’s bottom.
Add Pasta and Liquids: Pour in the uncooked penne pasta, fire-roasted diced tomatoes with their juices, and chicken broth. Stir everything together so the ingredients are well mixed. Cover the skillet with a lid and bring the liquid to a boil.
Simmer Until Tender: Once boiling, reduce the heat to medium-low and let the pasta simmer, uncovered or lightly covered, for about 10 minutes. Stir occasionally to prevent sticking. The pasta should absorb most of the liquid and become tender while the sauce thickens.
Finish with Cream Cheese: Add the cream cheese chunks to the skillet and gently stir until they melt completely, creating a rich, creamy sauce that coats the pasta and chicken.
Garnish and Serve: Sprinkle the sliced green onions over the pasta before serving for a fresh, mild onion flavor and a pop of color