Bring a large pot of salted water to a boil. Add the macaroni noodles and boil for a full 20 minutes. (No that is not a typo, cook this pasta for 20 minutes!) Drain the macaroni and set aside.

Meanwhile, make the cheese sauce. In a large pot over medium heat melt your butter. Whisk in the flour, salt and paprika, stirring constantly. Add your milk a little at a time, whisking it in completely before adding more. Once all the milk has been added, whisk for 1-2 minutes until the sauce is thick.

Temper the egg yolk by adding a spoonful of the hot milk mixture to the egg yolk and immediately whisk together. Wait a minute and repeat this same process. Then, add the egg yolk mixture to the pot of the milk mixture and whisk in.

Reduce the heat to low and begin to add your cheese. Tear the american cheese into pieces and add to the pot. Add in half of the cheddar and all of the italian blend. Whisk to combine and melt the cheeses consistently, until all the cheese is incorporated into the milk mixture. This might take 10-12 minutes of constant whisking. You can tell that it's fully incorporated when you lift the whisk and melted cheese is not pulling away from the sauce.

When the cheese is all melted and smooth add in the noodles. Stir gently until everything is combined.

Place the macaroni and cheese in a 9x13 dish. Top the macaroni and cheese with the other half of the cheddar cheese. Place under the broiler of your oven until just browned.  Do not take your eyes off of it or it will burn! Remove from the oven, cool slightly and serve. Enjoy!