Cook the macaroni until slightly al dente, it should be slightly firm. Drain.
- In a small bowl, beat the egg.
In a large pot, melt the butter and sprinkle in the flour. Whisk together over medium low heat, cooking the roux for five minutes.
Take 1/4 cup of the roux and slowly pour it into the beaten egg, whisking constantly to avoid cooking the egg. Whisk together until smooth.
Pour egg mixture into the roux, whisking constantly. Stir until smooth, add cheese, and stir to melt.
Whisking constantly, pour in the milk, add the mustard and truffle hot sauce. Whisk until smooth.
Cook 5 minutes until very thick. Reduce heat to low. Add salt and pepper.
Pour the drained cooked macaroni into pot and stir to combine.
Serve immediately or pour into a buttered baking dish and top with extra cheese. Bake at 350° for 20 to 25 minutes, or until bubbly and golden on top. Top with drizzles of Terrapin Ridge Farms Truffle Hot Sauce. Enjoy!