Soak the gelatine in cold water. Then squeeze well, heat 25 ml chicken soup and dissolve the gelatin in it. Finely chop the ham and cut the cheese into small cubes. Put half of the ham with the cheese cubes in a bowl and puree finely with 100 ml chicken soup using a hand blender. Fold in the gelatine. Whip the whipped cream until stiff, then beat the egg whites until stiff peaks form. First fold the whipped cream, then the beaten egg whites carefully into the ham and cheese mixture and season with pepper. Pour the mousse into a soufflé dish, smooth it out, cover with foil and refrigerate for at least 3 hours.