Preparation

1. Bring a pot of salted water to a boil and cook the penne until just al dente. Save about 1 cup of pasta water, then drain.
2. Cut the chicken into bite-sized pieces and pat dry with paper towels.
3. Season the chicken with Cajun seasoning and a little black pepper.

Cooking

1. Heat a large skillet over medium-high heat and add 1 to 2 tablespoons of butter.
2. Add the chicken in a single layer and cook until browned and cooked through, about 3 to 5 minutes per side. Remove to a plate.
3. Lower heat to medium, add another tablespoon of butter, and sauté minced garlic for about 30 seconds.
4. Pour in the chicken broth and scrape up any browned bits from the pan.
5. Add the cream and let it gently simmer for a minute or two.
6. Turn heat to low, and stir in the cheddar and parmesan a handful at a time until melted and smooth.
7. Add the cooked penne and chicken back into the skillet and toss until everything is coated. Use a splash of pasta water as needed.
8. Taste and adjust seasoning. Finish with parsley or a squeeze of lemon if desired.