1 cup macaroni
1/2 cup milk
1 cup heavy cream
2 cups shredded Cheddar cheese
1 (8 ounce) package cream cheese
2 egg yolks
1 cup butter
1 onion, finely chopped
Preheat oven to 375 degrees F (190 degrees C).
Bring a large pot of lightly salted water to a boil. Add pasta and cook for 8 to 10 minutes or until al dente; drain.
Combine milk, cream cheese, cream cheese, egg yolks and butter; stir well. Stir in onions and cook until all liquid evaporates from the mixture. Stir in Cheddar cheese and cook until cheese has melted
Spread mixture into 9x13 inch baking dish. Top with pasta and pick out any small crumbs that may stick to sauce. Pour milk out over top and sprinkle with Cheddar cheese. Cover with foil and bake in preheated oven for 1 hour and reduce the oven temperature to 325 degrees F (165 degrees C).