Preparation

• Toss the avocado, about one-quarter of the onion, 2-1/2 Tbs. of the lime juice, and 2 Tbs. of the cilantro in a medium bowl. Season with salt and pepper to taste and set aside.
• In a food processor, combine 1 cup of the beans, the tomatoes and their juice, the chipotles, and adobo sauce and process until smooth. Set aside.
• Season the chicken with 1 tsp. salt and 1/2 tsp. pepper. Heat the oil in a large Dutch oven or casserole over medium-high heat until it’s shimmering hot. Add the chicken (the thighs should just fit, evenly spaced) and sear without touching until golden brown, 3 to 4 minutes. Flip and cook the other side until also golden brown, 3 to 4 minutes. Transfer to a large plate and let rest for 10 minutes.
• Take the pot off the heat and set aside. When the chicken has rested, shred it by hand or chop it coarsely.
• Return the pot to medium-high heat. Add the remaining onion to the pot and cook, stirring, until the onion begins to brown and soften, about 3 minutes. Add the chili powder and cumin and stir for 20 seconds. Add the beer and cook, scraping the bottom of the pan with a wooden spoon to incorporate any browned bits, until it almost completely reduces, 3 to 4 minutes. Add the remaining white beans and the puréed bean mixture and bring to a boil. Stir in the chicken along with any accumulated juices on the bottom of the plate. Cover, reduce the heat to medium-low and simmer for 15 minutes so the chicken finishes cooking and the flavors mix and meld. Stir in 1-1/4 cup of the cilantro and the remaining lime juice and season with salt and pepper to taste.
• Ladle into large bowls and serve immediately with a generous spoonful of the avocado mixture, a dollop of sour cream (if using), and a sprinkling of the remaining cilantro.

Serve with Mexican rice or cornbread.