Rinse strawberries, trim and puree finely with the lemon juice and powdered sugar in a blender. Press the puree through a fine sieve.
Preheat oven to 140°C (approximately 275°F)
Beat egg whites until stiff, add 3 tablespoons of water and continue beating. Sprinkle in the sugar and vinegar gradually while beating. Gently fold in the strawberry puree.
Using a tablespoon, place 8-12 small dollops on a baking sheet lined with parchment paper. Press flat slightly and bake in preheated oven for about 30 minutes. Remove, cool and serve.