The day before for the sorbet, warm the rum pot and lemon peel slightly so that the flavours combine. Drain the cherries while collecting the juice. Remove the lemon peel from the rum pot. Purée the rum casserole, cherries and approx. 5 tbsp. cherry juice.
Pour into an empty clean ice container (approx. 1 l capacity). Cover and freeze for about 6 hours, stirring with a fork about every 2 hours.
The next day, cut the vanilla pod lengthwise for the zabaglione and scrape out the pulp. Mix with sugar, egg yolk and wine in a metal bowl. In a hot water bath (water must not boil!) whisk for 10-12 minutes to a white, airy cream. Then stir cold in a cold water bath.
Shortly before serving, whip cream until stiff and fold into the zabaglione. Cut off the sorbet balls (refreeze the rest) and arrange on plates with the zabaglione cream.