Put the ice machine in the fridge at least 24 hours before you start. Break the chocolate into small pieces. Separate the egg yolks from the egg white.
Whisk the egg yolks together with the sugar and the cornflour until it’s a nice, sticky schlop. Keep the egg white to make meringues.
Heat up the milk until right before it cooks. Now slowly pour it into the egg-schlop while you keep stirring.Heat up this mixture again right until it becomes thick. Take it off the heat right away, or it will turn into a rather disgusting scrambled egglike blobby thing. Break 200 grams of chocolate into little pieces and mix it into the custard until it’s all melted. Put the custard in the fridge and wait until it’s cold.
Take out the cold custard, mix it well with the cold cream. Now, pour it into the ice cream maker and turn it on immediately.
Melt the remaining 100 grams of chocolate. Au-bain-marie is the best way to do this. At the moment when the custard in the ice machine starts to become more icecream-like pour the liquid chocolate into the ice cream maker. It will break into small pieces of chocolate. When the ice cream is done, serve it right away — with or without meringues — and eat it all.