This stovetop dessert pairs dark chocolate with the earthy, nutty notes of toasted sesame. Slightly warm, the pudding is creamy; chilled, it has the consistency of firm custard. We preferred Dutch-processed cocoa for its rich, dark color, but natural cocoa, which has a lighter hue, worked, too. For a little more chocolate intensity and slightly less sweetness, use bittersweet chocolate instead of semisweet.