Chicken Tinga

2 bone-in, skin-on chicken breast halves (about 1 1/4 pounds; 550g)
Kosher salt and freshly ground black pepper
2 tablespoons (30ml) lard or vegetable oil
6 ounces tomatillos, peeled (170g; about 2 medium)
6 ounces ripe plum tomatoes (170g; about 2 medium)
4 medium garlic cloves
1 small white onion, finely chopped
2 teaspoons dried oregano (preferably Mexican)
2 bay leaves
2 tablespoons (30ml) cider vinegar
2 cups (475ml) homemade or store-bought low-sodium chicken stock (or water)
2 to 3 canned chipotle chiles in adobo sauce, plus 1 tablespoon (15ml) sauce from can
2 teaspoons (10ml) Asian fish sauce

Season chicken generously with salt and pepper. 

Heat oil in a medium saucepan over high heat until shimmering. Add chicken skin-side-down and cook, without moving, until well-browned, 6 to 8 minutes. (Lower heat if pot is smoking excessively or chicken starts to burn). Flip chicken and cook on second side for 2 minutes. 
Transfer to a large plate. 

Immediately add tomatillos, tomatoes, and garlic to pot (don't need to chop). Cook, flipping occasionally, until blistered and browned in spots, about 5 minutes.

Add onion (chopped) and cook, stirring, until softened, about 2 minutes. 

Add oregano and bay leaves and cook, stirring, until aromatic, about 30 seconds. 

Add vinegar and stock. Return chicken to pot, bring to a boil over high heat, then reduce to a bare simmer. Cover pot and cook, turning chicken occasionally, until chicken registers 145°F (63°C) when an instant-read thermometer is inserted into the center of thickest part, 20 to 30 minutes. Transfer chicken to a bowl and set aside. Continue cooking sauce at a hard simmer, stirring, until reduced to about half its original volume, about 5 minutes longer.

Add chipotle chiles and adobo, remove and discard bay leaves, and blend sauce using an immersion blender or by transferring to a countertop blender. Sauce should be relatively smooth, with a few small chunks. When chicken is cool enough to handle, discard skin and bones and finely shred meat. Return it to the sauce. Add fish sauce and stir to combine.

Bring to a simmer and cook, stirring, until sauce thickens and coats chicken. It should be very moist but not soupy. Season to taste with salt and pepper (if necessary).
originally from: https://www.seriouseats.com/chicken-tinga-spicy-mexican-shredded-chicken-recipe