An easy no-hassle meal
Preheat oven to 375 degrees F. In a greased or foil-lined pan, place your chicken breasts. Give a quick spray with cooking spray, then as heavily as you like it, cover the chicken with Cajun seasoning. (If you don't have Cajun, chili pepper, cumin, paprika, garlic, and cayenne work, too.) Bake for 45 minutes.
In a large pot, melt butter over medium heat. Add flour and whisk to make a roux. You want a light roux, so only 3-4 minutes. Until it's a light beige and has really formed together.
Whisk in the milk slowly. Once it is combined, whisk in the broth. Once that is combined, stir in the parmesan and garlic (and any salt, pepper, or red pepper flakes). It'll be runny, but make sure it's all combined well. Add more cheese if needed.
Bring to a boil, then add pasta. If using something long like a fettuccini, you'll have to stir and readjust to make sure all pasta gets in the sauce. Let it boil on medium for a minute or so, stirring occasionally to make sure the pasta does not stick to the pan. Cover with a lid, and reduce heat. Let it cook for about 15 minutes or until all pasta has cooked and sauce has thickened.
If chicken finishes before the pasta, cover loosely and let sit. This will actually make it easier to slice later. Once pasta is plated (you can garnish with parsley), slice the chicken and top on the pasta. Depending on appetite, it can make 2-4 servings. (For four, divide the breasts up between the plates.)