Beat egg whites until stiff. Add 36 g diabetic sweetener and salt. Stir in egg yolks one after the other. Mix flour and starch, sieve onto the foam and fold in carefully.
Line a baking tray with baking paper and draw 4 circles (each 12 cm Ø). Spread 2/3 of the dough into the circles. Bake in the preheated oven (electric: 200 °C/ gas: level 3) for 9-10 minutes.
Remove the omelettes from the baking paper and immediately fold over 4 glasses. Leave to cool. Bake two more omelettes from the remaining mixture as described. Stir mascarpone, curd and lemon juice until smooth, season with sweetener.
Put the cream in a piping bag with a large star-shaped spout and fill the omelettes with the cream. Spread cranberries over the omelettes and sprinkle with the rest of diabetic sweetness.