Watermelon Parfait

For the watermelon ice cream, boil the sugar with approximately 1/2 cup of water for about 1 minute, then remove from heat and let cool. Cut the melon flesh into small cubes and puree in a blender. Mix with the sugar syrup and lemon juice, and pour it into a rectangular metal pan. Freeze at least 2 hours.

For the lime ice cream. Soak the gelatin. Beat the egg yolks with the sugar and vanilla sugar until mixture is creamy. Grate the zest from the lime, squeeze the juice, and mix both with the lemon juice. Pour the mixture into a pot with the egg yolk mixture and cook over medium heat, whisking constantly until the mixture is thick, but do not boil! Remove the mixture from the heat and continue beating to prevent lumps from forming. Stir in the soaked and well squeezed gelatin. Allow the mixture to cool, stirring occasionally and refrigerate.

Beat the whipping cream until stiff and fold with the sour cream into completely cooled ice cream base. Pour the ice cream mixture on the separate frozen watermelon ice cream, smooth out and freeze 2-3 more hours.