Heat oil in a large pan over medium-high heat. Sauté onion, celery, 1 tbsp cilantro and garlic in pan until onion softens, about 3 minutes.
Add pork; cook, stirring, until meat is browned on the outside, 10 minutes.
Add hominy, poblanos, tomatillos, cumin, chili powder, stock and coriander, if desired; season with salt and pepper. Cover; simmer until pork is tender and white, 45 minutes. Stir in remaining 1 tablespoon cilantro; serve.