Chicken and Black Bean Stew

1 tablespoon vegetable oil
8 ounces smoked sausage, such as andouille or kielbasa, sliced into 1/4 inch disks
1 medium onion, diced (about 1 cup)
2 teaspoons ground cumin
2 (4-ounce) cans diced green chilies (preferably Hatch)
8 ounces dried black beans
12 stems cilantro, leaves roughly chopped, stems tied together with a piece of kitchen twine
4 chicken legs, divided into thighs and drumsticks (about 2 pounds)
1 quart homemade or store-bought low-sodium chicken stock
Kosher salt and freshly ground black pepper
Sour cream, for serving
Lime wedges, for serving

Heat oil in a pressure cooker over medium-high heat until shimmering. Add sausage and cook until starting to crisp around edges, about 2 minutes. Add onions and cook, stirring, until softened, about 3 minutes longer. Add cumin and cook until fragrant, about 30 seconds. Add chilies, dried black beans, cilantro stems, chicken, and broth. Season gently with salt and pepper and stir to combine.
Seal pressure cooker and bring to high pressure. Cook for 40 minutes. Cool pressure cooker under a cold running tap (if using an electric cooker, use the quick release valve), and open. Using tongs, transfer chicken pieces to a bowl. Discard cilantro stems. Return beans to high heat and continue cooking, stirring, until reduced to a thick, stew-like consistency, about 5 minutes. Meanwhile, shred chicken from bones and discard skin.
Stir chicken into beans, season to taste with salt and pepper, stir in half of chopped cilantro, and serve, passing sour cream, lime wedges, and remaining cilantro at the table.