Combine first 4 ingredients; stir well. Spread 3/4 cup mixture in bottom of a 13- x 9- x 2-inch baking dish.
Combine chicken, pepper, black beans, and 1/2 cup tomato sauce mixture in a medium bowl. Stir well. Spoon chicken mixture evenly down centers of tortillas. Roll up tortillas; place, seam side down, on sauce mixture in baking dish. Top with remaining sauce mixture and cheeses. Cover and bake at 350° for 25 minutes. Top with sour cream, and sprinkle with green onions.