Cook the pasta according to packet instructions in salted boiling water until almost completely cooked but still with a firm bite then drain off. Heat the iron skillet up over a medium low heat. Add in the butter and allow to melt down slowly. Add in the flour and stir into the butter, add in half the milk and combine by stirring continuously. Do this until most of the lumps are gone.
Season with black pepper and a pinch of salt, then grate in some nutmeg to taste (don't add too much as it's a strong flavour). Keep mixing over the heat for a few minutes until it becomes smoother then add in the garlic granules and after stirring through the sauce add in half the grated cheddar cheese. Stir the cheese gently through.
Preheat your ovens grill to medium. Add the cooked drained pasta into the skillet, season again with salt and pepper to taste if needed. Add the remaining milk little by little until you achieve a nice consistency to the sauce (you may not need to use all the milk). Stir through well until the pasta is evenly coated in the thick cheese sauce.
Sprinkle over the other half of the cheese and grill until golden and bubbly. Remove from the grill and sprinkle over the crispy onions. Grill for a further minute or two then it's ready. Enjoy! :)
