Cook elbow macaroni according to package directions. Drain and set aside.

Melt butter is a large deep pot over medium heat. Whisk in the flour and cook while whisking. Be careful not to burn the mixture. Add the milk, a cup and a time while stirring. Bring to a simmer and cook while whisking until the mixture thickens and bubbles. Remove from heat. Stir in the gruyere, cheddar, salt, pepper, and nutmeg. Mix with the cooked noodles.

Stir in the prepared pulled pork and serve.