Bring a large pot of water to a rolling boil and add 1 tablespoon of salt. Cook the linguine according to package directions until al dente. Reserve 1/2 cup of the pasta cooking water, then drain, cover, and keep warm.

Pound the chicken breasts to an even thickness. Season thoroughly with 1½ tablespoons of Cajun seasoning, ensuring the surface is evenly coated.

Heat the olive oil in a large non-reactive skillet over medium-high heat. Add the chicken and sear on both sides until golden. Reduce the heat to low and continue cooking until the internal temperature reaches 165°F. Transfer to a cutting board, slice into thin strips, and cover to retain warmth.

Using the same skillet, melt the butter over medium heat. Sauté the minced garlic for 30–60 seconds until aromatic, then add the diced tomatoes and cook for an additional 2 minutes.

Pour in the heavy cream, incorporate the remaining Cajun seasoning to taste, and stir in the Parmesan cheese. Allow the mixture to reach a gentle simmer, seasoning further if necessary.

Return the sliced chicken and cooked pasta to the skillet, tossing until the pasta and chicken are thoroughly coated and heated through. If needed, add a small amount of the reserved pasta water to adjust the sauce’s consistency. Serve immediately, garnished with freshly grated Parmesan and chopped parsley.