Preheat the oven to 400°F (200°C). Lightly spread a few spoonfuls of enchilada sauce across the bottoms of two 9×13-inch baking pans.
Make the filling: in a very large bowl combine the shredded chicken, cooked rice, drained corn, rinsed black beans, chopped green bell pepper, chopped onion, minced garlic, canned jalapeños or diced green chiles, cream of chicken soup, softened cream cheese, and 1 cup of the shredded cheese. Stir until evenly combined.
Assemble the enchiladas: spoon about 1/2 cup of the filling along the edge of each tortilla, sprinkle a small handful of shredded cheese on top, then roll the tortilla tightly and place it seam-side down in one of the prepared pans. Fit about 7–8 enchiladas per pan.
Pour and top: divide the remaining enchilada sauce evenly over both pans, covering the tops of the rolled tortillas. Sprinkle the remaining shredded cheese over the sauce.
Bake the enchiladas at 400°F (200°C) for 15–20 minutes, or until the cheese is melted and bubbly.
Serve warm with salsa or pico de gallo if desired.