Source: Thomas Keller's Bouchon Notes:  I just purchased a set of these mini Weck jars and love them especially for these pots de crèmes, which are traditionally baked in lidded vessels. The original recipe calls for using eight 5- or 6-oz pot de crème molds. Of course, if you have 4- or 6-oz ramekins, those will work, too. The mini Weck jars are much smaller (2.7-oz), which is kind of nice for such a rich dessert, but again, use what you have. Chocolate variation: Finely chop 6 ounces semisweet chocolate and place in a metal bowl. Then, in step 2, when you strain the mixture, strain it into a saucepan instead of a measuring cup. Heat the custard until it is warm, then pour it over the chocolate, let it sit to melt, then whisk it together until it has combined. Proceed with recipe.