Stone the cherries either with a pitter or by poking a drinking straw up through the cherry coming out at the stalk side.
Heat the cherries with the water and cook till softened. Use a wand blender to blitz them till smooth.
Heat a small pan of water with a bowl placed on top (water must not touch the base of the bowl) or use a double boiler.
Pour in the cherry pulp and add sugar, brandy and pinch of salt. Stir to dissolve the sugar.
In a separate bowl whisk the eggs and then pour them into the cherry mixture and continue to stir.
Chop the butter into small pieces and add this to the mix and continue to stir.
Keep stirring till the mixture thickens, about 20 minutes.
Spoon into sterilised jars.
This will keep for up to a month in the fridge and makes approximately 3 small jars.