Toast the buckwheat in a frying pan, then leave to cool. Mix together with the first part of the cream.
Heat the second part of the cream, then add it to the hydrated gelatine. Pour onto the chocolate and make an emulsion.
Add the first cream mixture, the n mix it all together, then strain through a chinois.
Keep refrigerated at 4 °C. Make the cream the day before.
For a more intense toasted rice or buckwheat flavour in the mixtures, the quantity of these ingredients can be increased by 10%-15% in the recipes for the rice pudding and the whipped buckwheat ganache.