2 1/2 pounds pork shoulder, trimmed and cut into 1-inch cubes
4 oranges, juiced
1 (14.25 ounce) can low-sodium chicken broth
1 onion, sliced and separated into rings
1 teaspoon dried oregano
3 dried ancho chiles (poblanos), stemmed and torn into small pieces
2 cups boiling water
1/4 cup apple cider vinegar
1 jalapeno, seeded and chopped
2 garlic cloves
2 tablespoons chopped cilantro
1/4 teaspoon ground cumin
Combine pork, orange juice, broth, onion, and oregano in the inner pot of an electric pressure cooker (such as Instant Pot(R)). Close and lock the lid. Select high pressure according to manufacturer's instructions; set timer for 20 minutes. Allow 10 to 15 minutes for pressure to build.
Release pressure using the natural-release method according to manufacturer's instructions, 10 to 40 minutes. Unlock and remove lid.
Remove pork from the pot and drain. Transfer to a serving dish.
Place ancho chiles in a heat-proof bowl. Pour boiling water over chiles and soak for 15 minutes. Drain chiles, reserving soaking water.
Combine 1/2 cup chile soaking water, soaked ancho chiles, apple cider vinegar, jalapeno pepper, garlic, cilantro, and cumin in a blender. Blend to form a thick sauce. Pour sauce over pork and mix well.