Start by boiling a large pot of salted water. Once it’s bubbling, add your penne and cook it until just al dente—usually about 8–10 minutes. Don’t forget to reserve about half a cup of the pasta water before draining. Set the cooked pasta aside.
Pat your chicken breasts completely dry with a paper towel. This step is key for getting that golden sear. Season both sides with salt and pepper. Heat a bit of oil in a skillet and cook the chicken for about 6–8 minutes on each side, or until it’s nicely browned and cooked through. Let it rest a moment before slicing it into strips.
In the same skillet, melt some butter and add the minced garlic. Cook it for about a minute until fragrant. Then stir in the flour, whisking quickly to form a smooth paste. This is your sauce base.
Pour in your heavy cream and chicken broth (or the reserved pasta water). Bring it all to a gentle simmer while stirring. Then mix in the grated Parmesan and continue to cook for 2–3 minutes until the sauce thickens. Season it with a bit more salt and pepper to taste.
Now add the sliced chicken and cooked pasta to the skillet. Toss everything together until it’s evenly coated with that rich, cheesy sauce. Top with fresh parsley if you like a pop of green.