Walnut and chestnut chocolates

100g of 64% dark chocolate

405g of caster sugar

5 egg yolks

10g of instant coffee granules

1/2 vanilla pod

100g of walnuts

3 egg whites

100g of chestnut purée

6ml of liquid glucose

30g of glucose

15g of chestnuts, chopped

80ml of water

125ml of milk

125ml of double cream

75ml of whipping cream, whipped