This is a great fudge recipe which I make every year at Christmas. The better the chocolate, the better the fudge so try not to use plain supermarket chocolate chips – use good quality chocolate such as Ghirardelli or Lindt. Milk, semisweet, or a mix of chocolates work well. This uses less sugar than other other recipes so it's less sweet - people who don't usually eat fudge because they find it too sweet like this. I usually use semi-sweet or dark chocolate. Cooking time is the time it takes for the fudge to firm up.