Put the coconut, chocolate, sugar and cocoa In a medium saucepan. Turn onto a very low heat and stir while the mixture melts together. Once melted take off the heat. Put the mixture into the fridge to cool. I use a large flat saucepan to melt this mixture as it melts easily and then cools quickly without me having to put it into another container to cool in the fridge. I just put the whole saucepan in the fridge and cool.
Meantime line the mould you are using by spraying with oil spray. Let the paper/plastic overhang so it can be easily pulled out. Line the mould with glad go between, smoothing over the mould to get rid of wrinkles.
Put the chickpea water into the bowl of a mixer (or hand mixer). Add the sugar (100 gm) and the cream of tartar and beat the mixture till it is very thick and white. It will be like extremely thick meringue. Don't stop beating until it is super thick white and spoonable.
Fold this mixture through the chocolate base 1/2 at a time.
Spoon the chocolate ice cream into the mould and then freeze for 3-4 hours or overnight depending on how cold your freezer is.
Once frozen the ice cream can be removed and sliced. Wrap individually and store till needed or eat straight away.