Preheat the oven to 375 degrees. Brush olive oil onto bottom, and halfway up sides, of a 10 inch cast iron skillet. (A baking dish also will work.)
On a plate, mash 3/4 of the can of black beans. Add sour cream, garlic, lime juice, cumin and cayenne. Add salt to taste. Mix in chicken, corn, cilantro, salsa, the rest of beans, and 1 cup of cheese.
Spread onto bottom of skillet, then evenly sprinkle remaining cheese on top of the mixture. Bake for 20-25 minutes, until dip is bubbling and browned on top. Sprinkle with cilantro and then serve with chips!