Ingredients

Step by step

1. Heat the oven to 120°C, fan 100°C, gas ½. Line 2 baking trays with baking paper. Using an electric whisk, beat the egg whites in a clean bowl. Start with a low speed, increasing to high. Whisk for 3-4 minutes until you have a stiff meringue.
2. Add the sugar 1 tablespoon at a time, whisking in between additions until all the sugar is incorporated. Rub a little meringue between your fingers to make sure no sugar grains remain.
3. Once the meringue is smooth, whisk in the cream of tartar, vanilla and a pinch of salt.
4. Spoon into a large piping bag with a round nozzle 1cm wide. Use half the meringue mix to pipe 15 mushroom tops – a range of small and medium rounds about 3-5cm wide, 2cm high – onto the baking trays, a couple of inches apart (use a wet finger to press down any peaks). Dust with cocoa.
5. Pipe 10 bases 1-2cm wide, 3cm-6cm long. Transfer to the oven to bake for 1 hour. When the meringues are ready, they will pull off the paper easily – if not, pop them into the oven for a few more minutes. Cool for 1 hour; peel off the paper.
6. Melt the dark chocolate in a heatproof bowl over a pan of barely simmering water; don't allow the bowl to touch the water. Use a teaspoon to dollop chocolate into the middle of each upturned mushroom top. Press a base onto each mushroom top; leave to set at room temperature.