Heat olive oil in a large pot. Fry onions until softened, about 2 minutes. Add garlic and jalapeno pepper. Continue to fry for another 30 seconds.
Add corn, black beans, chicken, tomatoes, enchilada sauce, and chicken stock. Stir to get everything well mixed. Bring soup to a boil over medium heat.
Add salt, lime juice (if using), and shredded cheese. Stir until cheese has melted and is heated through. Turn off stove.
Serve warm topped with chopped cilantro, shredded cheese, and crushed tortilla chips.