Bring a large pot of generously salted water to a rolling boil. Add your 16 oz (450g) of penne pasta and cook according to the package directions until it reaches a firm al dente texture. Reserve 1/2 cup (120ml) of starchy pasta water before draining.

Place a large skillet over medium-high heat and add 1 tbsp (15ml) olive oil and 1 tbsp (15g) butter. Add diced chicken breasts, season lightly with salt, and sear undisturbed for 3-4 minutes to form a golden-brown crust. Flip and cook another 3 minutes until cooked through. Remove and set aside.

Reduce skillet heat to medium-low and add the remaining 3 tbsp (45g) of butter. Once melted, sprinkle in 3 tbsp (25g) of all-purpose flour and whisk vigorously for 1-2 minutes until slightly nutty.

Slowly pour in 2 cups (480ml) whole milk and 1/2 cup (120ml) chicken broth, whisking constantly to prevent lumps. Simmer gently for 3-5 minutes until the mixture coats the back of a spoon.

Remove the skillet entirely from the heat. Gradually sprinkle in the freshly grated 8 oz (225g) of white cheddar cheese, stirring gently until melted and glossy.

Transfer the cooked penne and seared chicken back into the skillet. Toss to coat thoroughly, using reserved pasta water if needed to thin the sauce. Garnish generously with fresh parsley and cracked black pepper.