Place chicken, cheese, onions and olives on tortilla shells. Roll up each shell and place in a 9x13-inch baking pan. Heat soup and broth together in a saucepan. Stir until well blended. Pour over tortilla shells. Bake at 350 degrees for 20-30 minutes. About half way through baking time, sprinkle remaining cheese on top and allow to melt. Serve as is, or with a dollop of sour cream.