2 tablespoons olive oil
11/2 cups cooked black beans (add just enough cooking liquid to cover the beans)
1 serrano chile, stemmed and minced (remove seeds for a milder sauce)
1/2 cup dark beer
salt to taste
In a large skillet heat the oil over high heat. Add the beans, serrano chile, and beer and bring to a boil. Reduce the heat to low and simmer for 5 minutes.
Transfer half the bean mixture to a blender and purée until smooth. To remove the bean skins, pass puréed beans through a sieve back into the skillet. Simmer for 2 minutes or until heated through. Season with salt and serve warm. Sauce will keep for up to 4 days covered and refrigerated. Makes about 2 cups.