The three mousses are made in the same way:
- Whisk the egg yolks with the sugar in a basin over hot water until pale and thick.
- Dissolve the gelatine in 30ml (2 tbsp) water.
- Stir the gelatine into the fruit purée and add lemon juice if specified.
- Whisk in the egg mixture and cool.
- Whisk in the quark and chill until just beginn