Place the green tomatillos, poblano pepper, and serrano chilis in a medium-sized pot. Fill with water and cook over medium heat until the tomatillos change from a bright green to an olive green color, about 8-10 minutes. Transfer to a plate.
While the tomatillos are cooking, heat 2 tablespoon oil in a large pot over medium-high heat and brown the pork pieces on all sides (they don't have to be fully cooked). Season with salt and pepper.
Place the cooked tomatillos and chilies into the blender along with the onion, garlic, cilantro, parsley and epazote. Add about 1 cup of the cooking water and blend until smooth.
Heat 2 more tablespoon of oil in the same pot used to brown the pork, and pour in the sauce. Add the oregano, bay leaf, thyme, one teaspoon salt (or to taste), and pepper, and chicken broth (or water). Bring to a boil, reduce the heat and simmer for 10 minutes.
Transfer the browned pork to the pot, bring to a boil, reduce the heat, and cook for 30-40 minutes or until the pork is soft and fork-tender.
Add the drained hominy and cook for an additional 5-8 minute or until warmed through. Check the seasoning and add more salt if needed.