Heat a tablespoon of olive oil in a large skillet over medium heat. Sauté the chopped red bell pepper, green bell pepper, red onion, and optional jalapeño for about 5-7 minutes until the vegetables are softened and fragrant.

Stir in one cup of drained black beans and one cup of sweet corn into the skillet, cooking for an additional 2-3 minutes until heated through. Next, add the shredded cooked chicken breast along with chili powder, cumin, garlic powder, and cayenne pepper. Mix well and cook for another 2-3 minutes.

Reduce the heat and add one cup each of Monterey Jack and Pepper Jack cheese to the skillet with the filling. Stir continuously for a few minutes until the cheeses are fully melted and gooey. Remove from heat and allow the filling to cool slightly.

On a clean surface, lay out an eggroll wrapper in a diamond shape. Spoon a generous amount of the cooled filling into the center, fold the bottom corner up, then fold in the sides tightly and roll away from you, sealing the edges with a little water.

In a mixing bowl, combine half a cup of mayonnaise, half a cup of sour cream, a tablespoon of buttermilk, chopped fresh cilantro, lime juice, and a pinch of garlic powder. Whisk until smooth and creamy, then refrigerate for about 30 minutes.

Heat vegetable oil to 350-375°F. Add eggrolls in small batches, frying for about 2-3 minutes on each side until golden brown and crispy.

Remove eggrolls from oil and place on a plate lined with paper towels. Serve hot with the creamy ranch dipping sauce.