Cook pasta: per package instructions until al-dente. Meanwhile preheat oven to 400 degrees.
Saute chicken: Sprinkle the cajun seasoning on both sides of the chicken. Meanwhile heat olive oil in a large skillet. Once hot add in chicken and cook for 6-7 minutes flipping halfway through or until fully cooked.
Alfredo Sauce: Heat butter in a medium saucepan until melted. Whisk in flour and stir constantly for 1 minute. Make sure to keep an eye on it so it doesn't burn. Slowly add in milk and bring to a simmer, stir continuously so the milk does not bubble out over the pan. Simmer for about 2-3 minutes then take off of the heat. Add in both cheeses and stir until combined and lump free.
Assemble: Add the pasta and Alfredo sauce to the skillet with the chicken and toss to coat the pasta. Transfer the pasta to a greased 13 x 9 pan and top with the 1/2 cup of cheddar cheese. Bake for 5-10 minutes or until the cheese is melted. You can also turn the broiler on at the end to get the cheese golden brown just make sure to keep an eye on it.
Serve: Immediately with fresh chopped parsley for garnish, if desired.
Notes
Original recipe from chefsavvy.com. Please do not publish my recipe or pictures without linking back to the original post. Thank you!