1. Blister and char the green chiles according to your favorite method. Steam in plastic bag for fifteen minutes. Remove skins. Slit chiles down the sides and remove seeds. Leave stems intact. You can do this while the beans are cooking. Refrigerate the chiles until they are needed.
2. Rinse beans in colander and pick over for stones. Place in four-quart pot and cover with water. Bring to boil and simmer for three min- utes. Allow beans to steep for at least two hours.
3. Add the onion, garlic, epazote, and chipotle chile to the bean pot. Simmer for about one and a half hours. Because of the presoaking method, these beans will cook faster. Taste for seasoning. Add salt.
4. While the beans are cooking, make the chipotle cream. Thin out the sour cream with the milk and stir in the chipotle. I prefer to use the dried chipotle (see Resources), pulverizing it in a mortar. The dried chile is not as over- powering as the chipotle en adobo.
5. When ready to serve place about one-fourth cup black beans drained of excess liquid, in each green chile. Arrange on a heat-proof platter and place in a preheated 350 degree oven for ten minutes just to warm. You may serve each chile in a pool of chipotle cream or pour some of the cream over the top. Sprinkle the cream with a little dusting of mild chile powder or sweet paprika for color. This is a good treat for vegetarians but meat-eaters have been known to eat many of these.