1. Sprinkle the pork with the salt, black pepper and chili powder.
2. In a soup pot, heat the canola oil over medium-high heat. Add pork and cook until lightly browned, about 4 minutes. Remove from pot.
3. Add the onion, celery, garlic, oregano and cumin to the pot; cook, stirring occasionally, about 3 minutes or until slightly softened. Add the chicken broth, hominy or corn, and tomatoes; bring to a boil. Reduce heat and simmer 10 minutes. Stir in pork and cook 5 minutes or until heated through.
4. Ladle soup into four bowls; top each with slices of the avocado and radishes and a lime wedge.