Soak the chestnuts overnight.
Take off any remaining peel and put in a pot.
Add the cocoa powder.
Put in the sugar.
Add the rind of a tangerine.
Put in the mixed spice.
Add the cloves.
Pour in the water.
Put on a moderate heat till it starts boiling.
Reduce the heat and simmer for about 50 minutes or until the chestnuts are tender. If necessary add some boiling water.
Generally it is served in mugs or small bowls and always piping hot.