Preheat oven to 375°F.
Heat 2 tablespoon of oil in a large Dutch oven over medium heat. Sear the pork on both sides until brown. Remove the pork shoulder and reserve.
Add the onion, garlic, jalapeno and red pepper flakes. Cook for 3–5 minutes, until fragrant.
Add the water, and broth and return the pork to the pan. Bring the mixture to a boil. Cover and place in the oven. Cook until the pork is tender, about 3½ hours.
Remove the pork from the broth and allow to cool, then shred with 2 forks.
Strain the broth, reserving 6 cups. Place the onion and garlic and jalapeño mixture in a blender with the reserved broth. Blend until smooth. Add back to the pan.
Add the diced tomatillos, hominy, shredded pork and seasonings. Bring to a boil and lower to a simmer. Cook for 5 minutes.
Serve in individual bowls with the garnishes on the side.
