40g cocoa powder (halve this!)
Sift the dry ingredients together.
Mix dry ingredients with 300ml of the milk.
Heat the remaining 500ml of the milk in a saucepan until you hear it get hot - you know, that dangerous 'I'm about to boil over' sound!
Pour the chocolatey milk into the hot milk and whisk until the mixture thickens. By this I do mean WHISK, no stirring with a spoon or fork, otherwise you will get little lumps that won't please the kids!
Remove from heat and pour into a bowl that you can place cling wrap over securely. The plastic wrap must touch the surface of the pudding with no air trapped beneath, otherwise a skin will form.
Place the bowl in the fridge overnight. The kids can enjoy the next day!