Sauté onion in a heavy-bottomed pot over medium heat with oil until softened. Stir in garlic and cumin. Add chicken broth, diced tomatoes and diced green chiles. Bring the mixture to a simmer, reduce the heat to low and cook for about 20 minutes. Stir in cubed pork loin and just heat through.
Serve in bowls topped with crumbled tortilla chips and shredded cheese. Garnish with lime wdges and cilantro if desired