Toast the nuts in a dry pan for 5 mins
until golden. Leave to cool. Roughly chop
25g and set aside. Heat the cream, milk
and sugar in a pan until nearly boiling.
Whisk together the eggs yolks in a small
bowl. Pour a little of the hot cream over
the eggs and whisk together.
Pour the egg mix to the pan and gently
cook for about 8-10 mins until thick
enough to coat the back of a spoon. Set
a medium-size bowl over another bowl of
iced water. As soon as the custard has
thickened, strain into the bowl, then stir
through the 150g hazelnuts. Leave to
cool a little, then pour the mixture into a
blender and whizz until smooth. Freeze
according to your ice-cream maker’s
instructions. Will freeze for up to 1 month.
For the sauce, heat the cream with the
coffee in a pan until boiling. Take off the
heat, stir the chocolate until melted, then
stir in the liqueur, if using. Serve scoops
of ice cream in bowls with some sauce
drizzled on top and the reserved
chopped nuts scattered over.