Heat oil in large pot or Dutch oven over medium-high heat. Sauté onion in oil until tender. Add salsa, cumin, oregano, and cayenne pepper.
Step 2
Add great Northern beans, black beans, corn, diced tomatoes, chicken, and chicken broth. Mix thoroughly, bring to a boil, reduce heat and simmer for one hour (see note).
Step 3
Right before serving, add cheese and stir until melted. Or, if you prefer, sprinkle the cheese on top of each serving.