Squeeze the lemons and measure 200 ml lemon juice. Mix juice and sugar in a pot. Stir until the sugar has dissolved. Then reduce to a syrupy consistency, allow to cool
Add Prosecco. Beat egg whites until very stiff and fold in. Let the mixture set in a metal bowl in the freezer for 4-5 hours. Stir vigorously with a whisk about every 30 minutes
Wash the strawberries, clean and chop up to 1 strawberry. Puree the strawberry pieces, vanillin sugar and jam
Cut 1 strawberry into 4 slices. Divide the lemon sorbet between 4 glasses. Add strawberry sauce. Decorate with strawberry and lemon slices
Depending on the season, you can also puree other fruits for the sauce, e.g. raspberries or apricots. The dessert can be perfectly prepared when guests arrive