Printen on a vegetable grater, coarsely grate (food processor will be too fine.
Beat the egg yolks and egg with a pinch of salt and sugar in a bowl on a double boiler until the mixture is almost white and thickens. Beat the mass cold.
Whip the cream until semi-stiff. Fold in the rum, grated prinet and cream.
Pour the mixture into a mold and put in the freezer for about 6 hours.
Mass results in approx.: 1000 ccm = one parfait shape.
As a drink I recommend Muscat Spätlese, e.g. from Alsace.