To prepare the filling, drain the cherries and pour the juice into a small pan. Add the lemon rind and cinnamon and slowly bring to the boil. Remove from the heat. In a bowl, mix the cornflour with a little water to make a paste and pour on half the hot juice. Blend well, stir it in to the juice in the pan, return the pan to the heat and stir until boiling. Reduce the heat,