Cook Boston butt pork roast, recipe link in post.
Preheat oven to broil.
Place tomatillos, poblano peppers, jalapenos, banana peppers, 1 small onion, and corn (optional) on shallow rimmed baking sheet. Place on rack positioned 10-12 inches below broiler. Broil until skins are charred on one side. Turn everything over and continue broiling until well charred on all sides; about 20 minutes.
Meanwhile, heat a cast-iron skillet over medium heat. Add cumin seed and dry toast for 2-3 minutes, shaking pan often until fragrant. Watch carefully so they don't burn. Remove from pan into a mortar and pestle to grind fine. Add pumpkin seeds to cast-iron skillet and toast for 3-4 minutes until slightly golden. Remove from pan and add to a food processor. Grind until fine. Reserve.
Remove vegetable tray from oven. Transfer tomatillos and onion to blender. Place peppers in a small bowl and cover with plastic wrap. Allow to steam for 5 minutes. Run under cool water, removing skins, stems and seeds. Place flesh in blender. Add garlic, cilantro, ground cumin and pumpkin seeds, along with 1 cup of chicken broth. Blend until well combined.
Heat 1 Tbl. oil in Dutch oven or large soup pot. Add half of diced onion and sauté until translucent; about 5 minutes. Pour in all but 1/2 cup of blended tomatillo mixture. Simmer over medium-low heat for 20 minutes. Add in hominy, cubed pork, oregano, chili powder, salt & pepper. Heat through. Adjust seasoning to taste.
Ladle pozole into individual bowls, then pass garnishes.
