1. Place 1/4 cup water and beans in a medium saucepan; bring to a simmer.
2. Remove 2 chiles and 1 teaspoon adobo sauce from can of chiles; reserve remaining chiles and sauce for another use. Finely chop chiles; stir chiles and adobo sauce into beans; return to a simmer. Remove from heat; stir in juice, cumin, and salt. Mash with a potato masher to desired consistency; add additional water, if necessary. Sprinkle with cilantro, if desired.