Preheat oven to 400 degrees. In the meantime, over high heat bring a pot of salted water to a boil and cook the pasta for 10 minute. Until al dente. Drain and set to the side.
In a small saucepan add the butter and melt. Whisk in the flour and cook, stirring constantly until it forms into a paste. Cook until it slightly bubbles a bit, but not browned, about 1-2 minutes. Lower the heat and add the milk, continuing to whisk. Add the nutmeg, salt and pepper. Stir in the gruyere the last 2 minutes of cooking and continue too whisk until thickened and slightly bubbly.
In a large mixing bowl add the macaroni and melted cheese sauce and mix together with a wooden spoon. Scrape into a 3 quart baking dish working in batches. Layer a 1/3 of the macaroni and cheese and sprinkle with gouda, mild cheddar, white aged cheddar and 2 tablespoons butter, and continue to layer the macaroni mixture with the 3 different cheeses and butter. Sprinkle the top layer with any remaining cheese and the parmesan reggiano and breadcrumbs.
In a small bowl scramble the eggs and pour over the top of the macaroni and cheese. Cover with foil and bake in the oven covered for 30 minutes or until hot and bubbly. Remove from the oven and remove the foil. Adjust the oven setting to broil and place the baking dish back in the oven under the broiler for 2-3 minutes and broil until the top is golden brown.
Be careful not to burn as this process cooks quick! Remove and let set for 1-2 minutes. Serve.