Recipe of the week: chocolate macarons with fleur de sel

100ml whipping cream

1 vanilla pod, split

Note: This recipe must be prepared a day before serving.

For the chocolate macarons

Tip the sifted almonds, icing sugar and cocoa powder into a bowl; set aside.

In a separate bowl, whisk the egg whites until frothy. Add 10g of the sugar a little at a time, whisking until the egg whites are smooth and shiny. Gradually add the remaining sugar, whisking until stiff peaks form.

Slowly fold in a quarter of the almond-icing sugar-cocoa mixture. Cutting straight down to the bottom of the bowl with a spatula, and lifting up the contents, bring the spatula up the side of the bowl while giving it a quarter turn. Add the remainder in the same manner, in three separate batches. Stop folding as soon as the mixture is smooth and shiny.

Fit a piping bag with a plain round nozzle and fill with the macaron batter. Cover a baking tray with baking parchment; pipe 16 rounds of batter, 4cm-5cm diameter, on it. Set aside at room temperature for 20-30 minutes.

Preheat the oven to 160°C. Sprinkle a few sea salt flakes on the rounds of batter. Bake for nine minutes then lower the oven temperature to 120°C-130°C and continue baking for a further nine minutes.

Remove from the baking tray and cool on a rack; refrigerate when the rounded part of the macaron is hard.

For the ganache

Chop the chocolate and place in a bowl.

Beat the egg yolks and the sugar until pale yellow and creamy. Put the cream into a saucepan.

Using the point of a knife, scrape the seeds from the vanilla pod into the cream; add the pod and heat until simmering.

Quickly whisk a third of the hot cream into the egg yolk-sugar mixture. Pour into the remaining hot cream.

Stirring constantly with a wooden spoon, cook over low heat until the cream is thickened and coats the back of the spoon. (Do not allow to boil!) Remove from the heat immediately.

Strain over the chopped chocolate; stir until smooth. Set aside until cold; stir from time to time.

Fit a piping bag with a plain round nozzle, fill with the ganache; pipe balls of ganache onto the flat side of eight macarons; top with the remaining halves. Refrigerate for 24 hours when the centres will become moist.

From Le Cordon Bleu Chocolate Bible (Grub Street Publishing, £35)