Mix the milk with the cream, the sugar, the skimmed milk powder and the salt. Also grate the tonka bean on a fine grater. Mix it well and bring it to a simmer.
Meanwhile transfer the egg yolk in a bowl and while stirring slowly add the hot tonka liquid. Begin slow and then you can pour a bit faster. Pour it back into the pan and while stirring heat it up till the temperature is 85 °C (185 °F).
Then add the dark chocolate with the ice cream stabilizer. Blend it till smooth.
Once smooth pour it into a bowl, cover it and let it rest and infuse overnight in your fridge.
The next day you need to blend it for another 15 seconds. Then pass it through a super fine sieve and pour it into an ice cream machine. Turn it into a lovely ice cream.
Try to serve it as fast as possible, but otherwise keep it in a freezer that’s around -12 °C (10 °F).
