Cut the chicken breast into 1-inch bite-sized pieces and pat them dry with paper towels—this helps them brown better. Slice the red and yellow bell peppers into 1/4-inch thin strips, slice the red onion into 1/4-inch half-moons, and mince the garlic cloves. Combine 0.75 tbsp cajun seasoning with a pinch of salt and black pepper, then coat the chicken pieces evenly with this mixture. I like to season the chicken ahead of time so the flavors start to penetrate the meat before it hits the pan.

Heat 1 tbsp olive oil in a large pot or Dutch oven over medium-high heat until it shimmers. Working in batches if needed to avoid crowding, sear the seasoned chicken pieces for 2-3 minutes per side until golden brown on the exterior (it doesn't need to be cooked through). Transfer the seared chicken to a plate and set aside—the fond (browned bits) left in the pot will add tremendous flavor to the dish.

Add the remaining 1 tbsp olive oil to the same pot, then add the sliced bell peppers and red onions. Sauté for 3 minutes, stirring occasionally, until they soften slightly and begin to caramelize. Add the minced garlic along with 1.75 tbsp cajun seasoning and 0.5 tsp smoked paprika, stirring constantly for 1 minute to toast the spices and release their oils. This layering of aromatics and spices creates the deep Cajun flavor base that makes this dish special.

Pour in 32 oz chicken broth and 15 oz fire roasted tomatoes (with their juices), scraping the bottom of the pot to release all the fond. Bring to a boil, then add the 12 oz penne pasta directly to the pot along with 1 cup cream. Stir well to prevent the pasta from sticking. Return to a boil and maintain a gentle rolling boil for 12-13 minutes, stirring frequently to ensure even cooking and prevent sticking. The pasta will absorb liquid as it cooks, so consistent stirring is essential.

While the pasta cooks, mix 2 tsp cornstarch with 2 tbsp water to create a slurry. When the pasta is tender but still slightly al dente (after about 12-13 minutes), stir the cornstarch mixture into the pot and cook for 1 minute to thicken the sauce. Remove from heat, then add the seared chicken back into the pot along with 0.75 cup freshly grated Parmesan cheese and 3 tbsp fresh parsley, stirring gently until the cheese melts completely. Taste and adjust seasoning with additional salt and black pepper as needed before serving.