Heat the oven to 350 degrees. Spray a 13x9-inch glass baking dish with cooking spray. Spread about 3/4 of one of the cans of enchilada sauce in bottom of dish. Combine the beans, chicken, onions, 1 cup of the cheese and 1/2 cup of the sour cream in large bowl; mix well. Spoon about 1/2 cup of the mixture on each tortilla. Roll up tightly from the bottom, folding in the sides. Place in a dish. Top with the remaining enchilada sauce, spreading to cover completely. Bake the enchiladas for 40 to 45 minutes or until bubbly and thoroughly heated. Top with the remaining cheese during the last 3 minutes of baking. Sprinkle with the cilantro. Top each serving with a dollop of the remaining sour cream. *Optional: red enchilada sauce may be substituted for the green enchilada sauce.