How to Make It
Preheat the oven to 325°. Set four 1/2-cup ramekins in a baking dish just large enough to hold them. In a small saucepan, heat the half-and-half with the cardamom over moderate heat just until small bubbles appear around the edge, about 2 minutes. Remove from the heat.
In a medium stainless steel bowl, whisk the egg yolks with the whole egg and sugar. Whisk in the heavy cream and vanilla, then slowly whisk in the cardamom cream. Strain the custard into a glass measuring cup and pour it into the ramekins.
Pour enough hot water into the baking dish to reach halfway up the sides of the ramekins. Cover the ramekins with aluminum foil and bake for about 50 minutes, or until the custards are set but still a bit wobbly in the center. Transfer the pots de crème to a wire rack and let them cool to room temperature, then refrigerate until chilled, at least 4 hours or overnight.