Wash the untreated lemon, dab dry and rub the peel. Bring 300 ml water, sugar and lemon peel to a boil while stirring until the sugar is completely dissolved. Let the syrup cool down
Squeeze both lemons. Beat the egg whites until stiff. Mix sugar syrup, lemon juice and beaten egg whites. Put the mixture into a bowl (preferably metal) and freeze for 2 1/2-3 hours. Stir thoroughly with a whisk about every 30 minutes
Wash the mint, shake dry and cut into fine strips, except for a little bit. Place sorbet in the refrigerator about 10 minutes before serving. Stir in mint strips and fill the sorbet into 4 dessert glasses. Decorate with the rest of the mint and possibly with lemon slices and zest
-Served in well-chilled glasses, sorbets stay cold for a long time
-sorbet filled with cold sparkling wine