Boil water in a large pot. Add a pinch of salt, pasta and boil until the desired firmness. While the pasta is cooking, add a layer of the cut garlic to inside of a saucepot. Then set heat to medium and melt butter, whisk in flour and cook for one minute. Whisk in milk and cook until it thickens. Season the sauce with salt, pepper and nutmeg. Stir the cheese into the sauce making a figure 8 motion until melted. Then stir in the mustard and remove from heat. Drain the pasta and put it back into the pot. Slowly pour the cheese sauce over pasta. Change seasonings to taste.