Wash, clean and halve the strawberries. Mix with lemon juice, orange liqueur and 2 tablespoons of sugar. Put them into an ovenproof dish. Separate the eggs. Whisk the egg yolks, 1 tablespoon of water and lemon zest, stir in the sauce powder.
Beat the egg white until stiff and allow the remaining sugar to trickle in. Carefully fold the egg yolk mixture into the beaten egg white and spread on the strawberries. Bake in the preheated oven (electric: 175 °C/ gas: level 2) for 12-15 minutes.
Dust with icing sugar and serve immediately.