This fudge is so rich and chocolaty, nutty, and decadent, made with heavy cream and unsweetened chocolate for a pure classic chocolate fudge flavor. I love the look and taste of roasted pistachios. I used salted pistachios which add a bit of salty contrast to the sweet fudge. Look for shelled pistachios in the bulk section of your grocery store, they are normally already roasted and lightly salted. If using un-roasted pistachios, lightly toast before using to enhance their flavor. You can substitute almost any other nut for the pistachios if you prefer, such as almonds, hazelnuts, pecans, or walnuts. Toast the nuts before using as toasting them brings out their wonderful nutty flavor.