Start by melting your butter on a medium-low heat.
Add in your chopped shallots, and sauté for about a minute.
Gently whisk in your all purpose flour and mix well.
Add in your milk and cheese, and mix everything together. Make sure the heat is kept on low to medium. You don't want it to be too hot!
Once the cheese has dissolved, you can add in your cajun seasoning and Frank's Red Hot.
Cook your macaroni according to package instructions but subtract a couple of minutes from the cook time.
Mix your cooked macaroni with your cheese sauce and pour the mixture into a baking dish.
Add the remaining cheese on top of your mac n cheese and broil for about 2-3 minutes in the oven until the top is nice and crispy.