Preparation Steps

• In a bowl, toss the chicken with 1 tablespoon of the Cajun seasoning and a good pinch of salt and pepper. Let stand for 10 minutes while you slice the peppers and onion and mince the garlic.
• Heat 1 tablespoon olive oil in a large Dutch oven over medium-high heat. Add half the chicken in a single layer and sear until lightly browned, about 2 minutes per side. Transfer to a plate and repeat with the remaining chicken, adding a drizzle more oil only if needed.
• Reduce heat to medium and add the remaining 1/2 tablespoon olive oil. Add the peppers and onion with a pinch of salt. Cook, stirring occasionally, until the edges soften and pick up a little color, 4 to 5 minutes. Stir in the garlic, remaining 1 tablespoon Cajun seasoning, and smoked paprika; cook 30 seconds until fragrant.
• Pour in the fire-roasted tomatoes and chicken broth, scraping the bottom of the pot to release any browned bits. Bring to a brisk simmer. Add the penne and stir well, pressing the pasta under the liquid. Cover and cook for 8 minutes, stirring once halfway through to prevent sticking.
• Uncover, stir in the heavy cream, and cook at a lively simmer, stirring often, until the pasta is just al dente and the sauce is brothy-creamy, 4 to 6 minutes more.
• Whisk the cornstarch with 2 tablespoons water. Return the chicken and any juices to the pot, then stream in the slurry while stirring. Simmer 2 minutes, until the sauce noticeably clings to the pasta.
• Remove from heat and fold in the Parmesan, parsley, and lemon juice. Taste and season with additional salt and pepper as needed. Let the pot rest 2 to 3 minutes before serving so the sauce can thicken slightly.