Mix together the fruit purées.
Place the gelatine leaves in a bowl of cold water and allow to soften.
Place half of the fruit purée in a saucepan and and bring to the boil. Remove from the heat and then add the softened gelatine leaves to the pan. Stir until dissolved and then stir in the rest of the fruit purée.
Place the water, sugar and glucose in a saucepan and heat to a temperature of 121°C.
Remove the pan from the heat and then add the fruit purée.
Whisk the egg whites until fluffy. Add the fruit syrup mixture to the pan a little at a time, whisking continually until all of the fruit is incorporated and the mixture is thick enough to hold its shape.
Mix together the icing sugar and the corn starch and then use this mixture to dust a silicone baking sheet. Spread the marshmallow mixture on to the silicone baking sheet and then sprinkle the icing sugar/corn starch mixture over the top. Place in the fridge and chill for 1 hour.
Dust a cook's knife with the icing sugar/corn starch mixture and then cut the marshmallow into squares. Place the marshmallow squares in a sieve and shake gently to remove any excess icing sugar.
«Serve the marshmallows with a drizzle of balsamic vinegar.»