Pot de crème tends to get short shrift in comparison to its fancy cousin, Crème Brûlée. That's unfortunate because it certainly isn't any more difficult to make. So I spiced it up to give it a chance to shine in its own right. I also reduced the sugar a bit to let the spicy notes stand out more. —boulangere
Preheat oven to 325 degrees. Set a pan containing a quart of water on the stove to heat.
Pour milk and cream into a stainless steel saucepan. Add ginger, cardamom, cinnamon, and the chile de arbol. Stir, then set over medium heat. Bring to a scald, then remove from heat and put a lid on the pot. Let spices steep for 30 minutes.
Whisk egg yolks together in a mixing bowl. Add the salt to the sugar, and add them to the yolks in a slow, steady stream, whisking continuously.
Break milk chocolate into pieces and place in a separate mixing bowl. Set a strainer over the bowl. Strain the milk and cream mixture into this bowl and let sit for one minute for the chocolate to melt. Discard spices. Stir mixture with a spatula to completely incorporate melted chocolate.
Temper chocolate mixture into the eggs and sugar by pouring in a slow, steady stream, and whisking all the while.
Divide among 4 ramekins. Break the piece of cayenne-chocolate into 4 sections. Drop one into each of the ramekins. This is going to put a little surprise down in the middle of your custards.
Set the ramekins on a baking sheet with 4 sides. Set the baking sheet in the oven. Pour the hot water into a large measuring cup or pitcher. Use that to pour hot water into the baking sheet so that it comes almost to the lip. Set a second baking sheet on top of the ramekins. This will prevent the custard from forming a skin on the surface.
Bake custards for 35-40 minutes. When done, they should still be a bit jiggly. I use a canning jar lifter to remove the custards from the oven. Don't try to lift the baking sheet full of hot water out of the oven until the water has cooled. Leave the door ajar, and the water should be cool enough to safely handle within a half hour or so.
Cool before serving, but it need not be refrigerator-cold. The custard will have more flavor if it's closer to room temperature. Top with a splosh of whipped cream.