Preheat the oven to 350°F Bring a large pot of water to a boil. add in the oil, chicken broth, or 1 cube of chicken bouillon. Add in the macaroni. Stir. Reduce heat and allow to cook for 5 minutes.
Drain and reserve a little pasta liquid for later. Set drained pasta to the side.
In the same pot, melt the butter and stir in the flour. Stir until paste like texture, Add the half-n-half, cheeses, and seasonings. Continue to stir gently. allow the sauce to thicken but not too thick.
Add the cheese sauce to the pasta and mix well. Allow the mixture to cool a bit before stirring in 1 beaten egg.
Spray olive oil spray or butter casserole dish and transfer the mac and cheese into the baking dish,
Use half of the mixture, then add another layer of shredded cheese and repeat until you reach the final layer of shredded cheese on top.
Cover with foil and Bake the mac and cheese for 15-20. Remove Foil and bake until it is nice and bubbly with a toasty brown crust.