The poetically named "drunken" beans are so called because they are cooked in beer, a recipe derived from northern Mexican cooking, where they are called "borracho" beans. It's the chipotle chiles that give the sauce its deliciously smoky quality. Tomatillos are common ingredients in southwestern cuisine, and they are widely available in cities around the country that have Hispanic or Caribbean populations. Tomatillos look like green tomatoes and belong to the same family, but they are more closely related to the Cape gooseberry, which also has a thin, papery, parchmentlike covering. The citrusy green apple flavor of tomatillos is transformed by blackening them, giving them robust, complex tones. If you use less water in the sauce to leave it thicker, you can make a great dipping salsa for chips.
