Bittersweet chocolate Pots de Creme

1. Preheat oven to 300 degrees. Move rack to center position. Heat some water in a kettle. 2. In heavy saucepan, bring cream and milk to a boil. Remove from heat, whisk in chopped chocolates until smooth. 3. In a large bowl, whisk together yolks, sugar and salt. Whisking constantly, slowly pour hot chocolate into yolks. Strain through a fine mesh sieve into a large measuring cup. 4. Divide mixture among 4 ramekins. Set cups in a large roasting pan and add hot water to pan, half way up sides of cups. Cover pan with foil; prick holes in foil with a sharp knife. 5. Bake until edges are lightly set (lift foil to check) but center is still jiggly, 30 - 35 minutes. (it will set as it cools) Transfer cups to a wire rack to cool completely. Refrigerate at least 3 hours before serving with creme fraiche, whipped cream or vanilla ice cream.