Break the stems off the chiles and shake out as many seeds as possible. Cover with boiling water and keep submerged with a coffee cup or a plate. Soak until soft, about 20 minutes.
Transfer the chiles, garlic, kosher salt and 1 1/2 cups of the soaking liquid to a blender and purée until smooth. You should have about 2 cups.
Season the pork all over with the salt and cumin. Brown on all sides in an Instant Pot (See Note 2) on Saute setting, Dutch oven or large stock pot with oil. Do not overcrowd the pan and steam the meat, do this in several batches.
Return all browned pork to pan, add the onion, celery, tomatoes, jalapeños and serrano chile and cook another 5 minutes.
Stir in the chicken broth, water, Mexican oregano, bay leaves and 1 cup of the chile puree, reserve the balance for later. Cover with lid and set IP to High Pressure for 35 minutes. If using a Dutch oven or large stockpot, bring to a boil, reduce the heat to low. Partially cover and cook, stirring the pork a few times, until tender, about 2 hours.
Allow for Natural release if using an Instant Pot. Stir in the hominy, white beans and remaining chili puree and simmer, uncovered for 15 minutes OR 30 minutes more if cooking on stovetop in a Dutch oven or large stockpot. Remove the bay leaves.
Serve with limes, diced avocados and chopped cilantro on top.
One (1) whole Guajillo or Ancho chile is roughly equivalent to one (1) heaping tablespoon of powder. So if I were to grind all, it would equal 10 tbsp chili powder + 1 teaspoon of red pepper flakes.
In this recipe I give times for using an Instant Pot and Dutch oven or large stock pot, but using the pressure cooker reduces the cooking time considerably.