Preheat the oven to 180C/350F/Gas 4. Grease and line a 26 cm (10 1/4 inch) springform cake tin.

Using an electric mixer, whisk the egg whites until soft peaks form then slowly add the sugar and continue to whisk until thick and glossy.

Add the egg yolks one by one, beating well after each addition.

Gently fold in the chocolate and nuts.

Pour the mixture into the prepared tin and bake for 45 minutes or until a skewer inserted into the middle comes out clean. The cake will dip a little in the middle when it comes out of the oven. Allow to cool in the tin.