Heat vegetable oil in a large saucepan over medium-low heat.

Add chopped onion and cook, stirring occasionally, until tender.

Stir in minced garlic, diced green chili peppers, cumin, dried oregano, and ground cayenne pepper.

Continue to cook and stir for about 3 minutes, until fragrant.

Pour in chicken broth, then add chopped cooked chicken breasts, white beans (drained), corn (drained), and diced tomatoes (undrained).

Bring the mixture to a boil, then reduce heat to low and let simmer for 20 minutes, stirring occasionally to prevent sticking.

Serve hot, sprinkled with shredded Monterey Jack cheese.