Cook Chicken: Pat chicken dry with paper towels and season all sides with 1 tablespoon of cajun seasoning. Bring a large cast iron skillet to a medium-high heat and add 1 tablespoon of butter to melt. Once hot, cook the chicken thighs for 5-7 minutes on one side, flip, and continue cooking for 5-7 minutes on the other side. Cook until the internal temperature at the thickest part of the meat reaches 162 degrees F (use an instant-read meat thermometer). Let chicken rest on a plate.

Boil Pasta: while the chicken is cooking, bring a separate pot of water to a boil. Add pasta and cook to al dente according to the package directions. Reserve 1/2 cup of the pasta water before fully draining.

Make Sauce: in the same large skillet used to cook the chicken, bring back to a medium high heat and add the rest of the butter to melt. Add garlic to the hot pan and move around until fragrant; about 30 seconds. Gradually add the heavy cream (or dairy-free alternative) along with the remaining cajun seasoning, diced tomatoes, salt and pepper. Whisk to combine, let simmer and reduce for about 10 minutes, whisking consistently. Once mixture has thickened, remove from heat and mix in the parmesan cheese to melt. 

Combine: Add cooked noodles to the skillet and toss to combine. Add splashes of reserved pasta water to thin, as-needed. Taste and more salt or cajun seasoning, if needed. Cut cooked chicken into strips and toss with the pasta in the pan.

Serve: enjoy immediately with some chopped parsley and/or parmesan cheese on top!