Wash the lemon, grate dry and tear off some of the zests. Squeeze 1/2 lemon. Wash, clean and chop 200 g strawberries. Puree the remaining strawberries, apple juice and vanilla sugar and season to taste with some lemon juice.
Place the strawberry pieces in the cold dish. Beat the egg white until stiff, adding sugar and salt. Beat until the mixture is shiny and the sugar has dissolved. Heat the water in a wide saucepan, do not let it boil.
With 2 teaspoons of dumplings, pierce the meringue and slide into the boiling water. Put the lid on and let it stand for about 5 minutes. Arrange cold bowl and snow dumplings in plates and decorate with lemon zests and pistachios.