Heat the oil in a large Dutch oven or heavy pot over medium heat. Add the bacon and cook until it renders much of its fat and crisps slightly, about 7 minutes. Transfer the bacon to a plate lined with paper towels.
Season the chicken well with salt and pepper. Add half of the thighs to the pan and brown them well on both sides, 2 to 3 minutes per side. Transfer to a plate. Brown the remaining thighs and reserve with the rest.
There should be 2 to 3 tablespoons fat left in the pan; if there's more, spoon out and discard the excess. Add the onion and bell pepper, season well with salt, and cook, stirring often, until the onion softens and caramelizes slightly, about 7 minutes. Raise the heat to high, add the chili powder and cumin, and cook, stirring, for 30 seconds.
Add the beer and cook until it's almost completely reduced, about 3 minutes. Add the beans, the chipotle and the chicken broth. When the mixture comes to a boil, adjust the heat to maintain a simmer and cook for 5 minutes.
Transfer 2 cups of the beans and broth (but not the chipotle) to a blender, purée, and then mix it back into the rest of the broth.
Return the thighs to the pot, cover with the lid slightly ajar, and simmer until the chicken is cooked through, about 30 minutes. If the stew is too thick, thin it with more chicken broth.
Discard the chipotle. Crumble the reserved bacon. Juice one half of the lime; cut the other half into wedges. Stir the bacon, lime juice, and 2 tablespoons of the cilantro into the stew and season well with salt and pepper.
Serve immediately. Sprinkle each serving with the remaining cilantro and a small dollop of sour cream. Serve with the lime wedges and fried tortilla strips, if you like.