Preheat the oven to 325 F. In a large, oven-proof, stock pot or Dutch oven combine pork and stock and heat over medium heat. Bring to a boil, reduce heat, and simmer for 30 minutes. Add tomatoes, onions, garlic, oregano, chipotle in adobo sauce, salt and pepper. Bring to a boil, remove from the heat, cover, and place in the oven. Braise for 2 hours.
Remove the pot from the oven, add hominy. Place pot over medium heat and simmer for 20 minutes. Stir in kale and lime juice and simmer for 2 minutes. Top soup with chopped scallions and serve.