Set aside a handful (about 50g) of the pitted cherries. Place the remainder in a large pan over a medium heat with the cream and 50g icing sugar. Bring to the boil and gently simmer for 5 minutes until the cherries start to soften. Carefully whizz in a blender and then sieve.

Add the egg yolk, whisk well the pour back into the pa. Simmer until the mixture has thickened a little and pour through a sieve into a bowl, cover the surface with cling film and leave to cool completely.

Whisk the egg whites until stiff peaks form, then whisk in the remaining 50g sugar, 1 tbsp at a time. Keep whisking until the mixture is stiff. Stir in a third of the mixture into the cooled cream, mix until it is incorporated then gently fold through the remaining mixture.

Line 900g/2lb loaf tin with cling film. Pour the mixture into the tin, the cover with cling film and place in the freezer for about 3 hours until it is just starting to freeze. Stir the whole cherries into the semi-frozen mixture, and then return to the freezer for at least 8 hours or preferably overnight.

Serve cut into slices with some cherries, or sandwich between wafers.