Carefully thinly slice the chicken breasts in half widthwise. Next, mix 3 tablespoons each of olive oil and Cajun spices on a large plate until combined.
Coat the chicken breasts on both sides in the spicy-oil blend until coated.
Add the remaining 1 tablespoon of olive oil to a large, non-stick skillet and turn the heat to high. Place the chicken breasts, turn the heat down to medium, and cook for 4 to 5 minutes per side until browned and cooked throughout. Set them aside on a plate.
Next, add the bell peppers and sauté in the pan for 1 to 2 minutes. They should still be crisp, and it’s okay to saute in any leftover oil and spices that were in the pan from the chicken. Also, set those to the side.
Add the garlic, white slices from the green onions, and butter and cook over medium heat while frequently stirring for just 30 to 45 seconds.
Pour in the chicken stock and cook over high heat for 3 to 4 minutes to reduce the amount of liquid by roughly 1/3.
In the meantime, drop the pasta in a large pot of boiling salted water and cook according to the package time. Be sure to stir occasionally.
Return to the pan of chicken stock, add in the cream, and cook for 3 to 4 minutes over high heat to reduce. Continue stirring.
Next, Stir in the cheese and cook over medium heat for an additional 3 to 4 minutes or until thickened.
Add the remaining 1 tablespoon of Cajun spices, sauteed peppers, and tomatoes and mix to combine.
Drain the pasta and add it to the pan, tossing until combined. You can also slice the chicken and mix it in or serve it over the top of the pasta with green slices of green onions.
Notes
Thin chicken cutlets cook quickly and can become dry and chewy easily, so keep a close eye on them while searing. You’ll know they’re cooked perfectly when both sides are golden brown and crispy, and the inside is no longer pink. Also, remember to let the seared chicken breasts rest off the heat for 5 minutes before slicing to allow those delicious meaty juices time to soak back into the meat.For a milder spice level: Cajun seasonings are naturally bold and slightly spicy thanks to the cayenne and paprika. If you’re sensitive to spice, reduce the Cajun seasoning blend to 2 to 3 tablespoons.Cajun chicken and shrimp pasta: For double the protein in this meal, sauté large shrimp coated in Cajun seasoning until they turn pink and opaque. Plate them on top of the pasta with the chicken.More vegetable options: Feel free to cook other veggies alongside the bell peppers, such as mushrooms, zucchini, or jalapenos. Spinach or frozen peas also work well but should be added towards the end to help them stay vibrant.Add andouille sausage: This spicy, smoked pork sausage is a staple in Cajun cuisine and tastes fantastic in this dish. Sauté the sliced sausage separately and toss it into the sauce with the pasta when ready. Slow cooker cajun chicken pasta: If you prefer a hands-off approach, season and sear the chicken as directed before adding it to a slow cooker with the peppers, onions, garlic, stock, and 1 tablespoon of Cajun seasoning. Cook on LOW for 4 hours or on HIGH for 2 to 3 hours. Before serving, stir the cooked pasta, heavy cream, and parmesan cheese into the crockpot and let everything meld for 10 minutes before serving. Make-Ahead: Pasta dishes with cream-based sauces like this are best served fresh off the stove.How to Store: If you have leftovers, store them in an airtight container in the refrigerator for up to 3 days. Avoid freezing, as the sauce may separate and become grainy once thawed.How to Reheat: To revive the leftovers, reheat the creamy pasta in a pan over low heat. Add a splash of water or stock and stir until creamy and heated through again.