Add the oil to a large pot and heat. Saut� the onion, garlic, and cumin in the oil until the onion is soft but not brown.
Add the drained and rinced navy beans, tomatoes with liquid, and chicken broth to the pan. Bring the mixture to a boil, and then reduce the heat.
Mix in the tomato sauce, oregano, green chiles, and chicken. Let simmer for 15 minutes.
Stir in the cilantro and 1 cup of cheese until melted. Serve with the tortilla strips on the side.