Step 1

Heat oil in a Dutch oven or large pot over medium-high heat until shimmering. Add chicken thighs skin-side down and cook until well browned, about 6 minutes. Flip thighs and continue to cook until other side is lightly browned, about 3 minutes. Transfer chicken to a plate, leaving fat in pan, and set aside.

Step 2

Add onions and garlic to Dutch oven and cook, stirring occasionally, until onions have browned around the edges, about 5 minutes. Add tomatillo and cook until browned around the edges, about 4 minutes. Add oregano and cumin and cook until fragrant, about 30 seconds. Add tomatoes, chipotle, and adobo sauce and stir to combine. Remove from heat.

Step 3

Transfer sauce to the jar of a blender and puree until smooth. Pour sauce back into pan, stir in chicken stock and bay leaf, and bring to a boil over medium heat. Nestle chicken thighs in sauce, reduce to a simmer, and cook until meat registers 165°F in thickest part of thigh on an instant-read thermometer. Transfer chicken to a plate and let sit until cool enough to handle. Remove sauce from heat and discard bay leaf.

Step 4

Pull chicken meat into strips, discarding skin, any large pieces of fat, and bones. Stir chicken into sauce and cook over medium heat until warmed through, about 3 minutes. Remove from heat and season with salt to taste.

Step 5

Spoon chicken into warm tortillas and top with tomatillo salsa, onion, cilantro, and cotija cheese. Serve with lime wedges.