Caramelised walnut and coffee pavlova

Method

1. Heat the oven to 100°C fan/gas ½. Draw a circle with a 25cm diameter on a sheet of baking paper, then put the paper on a baking tray. Put the cornflour, vinegar, coffee and vanilla in a small bowl and stir to dissolve the coffee, then set aside.
2. Whisk the egg whites in a spotlessly clean mixing bowl until they form soft peaks. Slowly add the sugar, 1 tbsp at a time, whisking continuously. Once the sugar is incorporated, whisk for a further minute until the mixture is glossy and stiff. Add the reserved coffee mixture and whisk for a few seconds.
3. Spread the mixture on the baking paper, using the circle to guide you and shaping the mixture to resemble a crater, with the sides a little taller than the centre. Bake for 1½ hours until the meringue is crispy and dried out. Set it aside to cool completely.
4. Meanwhile, put the walnuts, sugar and butter in a pan and cook over a low heat for 6-8 minutes until the sugar turns to caramel. Pour the mixture onto a sheet of baking paper and immediately separate the nuts. Set aside to cool, then roughly chop.
5. To make the ganache, put the chocolate in a heatproof bowl. Heat the cream until just below boiling, then pour it over the chocolate and stir until melted. Set aside to cool.
6. When ready to serve, make the topping. Put the cream and sugar in a large bowl and whip until the mixture forms soft peaks. To assemble the pavlova, put the meringue on a serving plate, top with the whipped cream, then drizzle over the chocolate ganache. Sprinkle the caramelised walnuts on top and serve immediately.