This is such a classic and, while many people start with a roux as a base, I like to warm cream and slowly add in cheese so there is nothing but pure cheese flavor. I find the flour from the roux dulls the other flavors and almost clashes with the floury nature of the macaroni itself. There are a few little bits of spice and added salt in this recipe. Worcestershire has anchovy in the base so if you want this dis to remain vegetarian, substitute soy sauce.