Pit cherries over a bowl. In a saute pan dissolve sugar in 1 cup water, add lemon zest and bring to a boil. Mix arrowroot with a little cold water to make a paste. Whisk arrowroot paste into boiling syrup and cook, stirring, until thickened. Add cherries and poach over low heat for 5 to 7 minutes until tender. Heat Kirsch in a separate saucepan. Pour over cherries and Carefully ignite with a long match. Shake pan until flames die down. Scoop ice cream into 4 glass bowls. Spoon cherries and syrup over and serve immediately.