Method

1. Set aside 50g/1¾oz of the chocolate for later, and temper the remaining chocolate. To temper, melt the milk chocolate in a bowl set over a pan of gently simmering water. Don’t let the bowl touch the water or the chocolate will burn and don’t let any water into the chocolate or the chocolate will seize.

2. Continue to heat the chocolate until it measures 42C/107F on a chocolate thermometer. Then take it off the heat and let it cool to 31C/88F.

3. Use a clean, grease-free brush or teaspoon to coat and line each of the fluted cups in the mould with the chocolate. You need to do this quickly or the chocolate will start to set and be too thick to work with.

4. Use a spatula to scrape away any chocolate from the top of the mould. Save any chocolate that you haven’t used to use again later.

5. Put the moulds in the fridge to set for around 20 minutes.

6. To make the filling, put the coffee essence in a measuring jug and add enough cold water to make it up to 50ml/2fl oz. Pour into a pan, add the sugar and bring to the boil. Simmer for one minute.

7. Put the reserved 50g/1¾oz of milk chocolate in a bowl. Add the coffee liquid and stir to help the chocolate melt, then leave until cold. Leave it to thicken up in the fridge for an hour or so before filling the moulds.

8. Take the moulds out of the fridge. Spoon the chocolate and coffee mixture into the moulds and leave to set overnight.

9. To seal the walnut whips, temper the remaining milk chocolate, using up any chocolate leftover from earlier.

10. Using a teaspoon, spoon the chocolate over the filling to cover.

11. Top each with a walnut. Chill for at least 30 minutes until set, then carefully upturn the mould onto a board to release the walnut whips.

12. Serve after dinner with coffee.