Caramelise 85 g sugar until golden brown. Add 3 teaspoons lemon juice and 1 tablespoon hot water. Stir until the caramel has dissolved. Divide into 4 greased, ovenproof moulds (approx. 150 ml content).
Refrigerate until the caramel is firm. In the meantime, whisk the egg, egg yolk, cream, milk and remaining sugar with the whisk of the hand mixer until creamy. Pour onto the caramel. Place the moulds in a water bath.
Allow to set in the preheated oven (electric cooker: 175 °C/ gas: level 2) for approx. 50 minutes. In the meantime, wash, halve and core the grapes. Sprinkle with remaining lemon juice. Wash lemon balm, pluck off leaves and mix with the grapes.
Turn the creamy caramel onto small plates. Arrange with the grapes and serve.