- 3 serrano peppers
- 1 (28-ounce) can of tomatillos, drained, or 15 fresh husked tomatillos broiled until charred
- 1 large handful cilantro, including stems, plus additional 1/4 cup leaves, chopped for garnish
- 1 small onion, quartered
- 3 medium cloves garlic
- 1 tablespoon fresh juice from 1 lime, plus additional lime wedges for serving
- 1 teaspoon cider vinegar
- Kosher salt
- 2 1/2 pounds chicken thighs
- 1 (4-ounce) can diced jalapeños, preferably fire-roasted, drained
- Corn tortillas
- Medium red onion, minced
Place peppers in a small pot of boiling water and simmer until color goes from bright green to green-gray, about 7 minutes. Drain and transfer to a blender or food processor. Add tomatillos, cilantro, onion, garlic, lime juice, and vinegar. Season with to taste with salt. Blend or puree until just combined but some texture remains.
Place chicken in the bowl of a slow cooker. Add jalapeños and prepared tomatillo mixture. Set to low and cook for eight hours.
Remove chicken thighs from slow cooker and let cool slightly. Discard skin and bones. Shred chicken using two forks, return to slow cooker, and stir to combine. Season to taste with salt. Serve with warm tortillas, chopped red onions, chopped cilantro leaves, and lime wedges.