Dipping Chocolate for Biscotti

Line two baking sheets with parchment paper. Melt the chocolate and the shortening in the top of a double boiler or in a heatproof bowl over barely simmering water, stirring occasionally until smooth. Remove the dip from the heat. Holding a cookie horizontally, dip one side of the biscotti into the mixture to cover the side and half of the top and bottom portions of the cookie. Place the biscotti, chocolate-dipped side down, on one of the prepared baking sheets. Repeat with the remaining biscotti. Transfer the baking sheets to a cool place and allow the chocolate to set, 45 to 60 minutes.