Preparation

• Line two baking trays with parchment paper.
  Prepare a piping pastry bag with a round tip.
  Place the almonds, icing sugar and cocoa in a food processor, and pulse to combine. Do this around 10 times, or until all the ingredients are mixed well together. Sift in a fine mesh sieve, twice.
  Place the egg whites and caster sugar in the bowl of a stand mixer fitted with a whisk attachment and whisk for 2 minutes at a low speed using a KitchenAid mixer.
  Increase to a medium speed for 2 minutes followed by a high speed for 2 minutes. The whisked egg whites should form a clump in the middle of the whisk. Remove the egg whites from the whisk and detach the bowl from the mixer before adding the almonds, icing sugar and cocoa.
  Fold the dry ingredients into the whisked egg whites, pressing against the side of the bowl. The goal here is to incorporate the dry ingredients, but also to deflate the egg whites. This should take about 40 strokes. The mixture is ready to pipe when it flows in ribbons off the spatula, like lava.
  Fill the prepared piping bag with half the mixture, sealing the open end with a twist.
  Pipe four dots of the mixture in the corners of the tray, under the baking paper, to secure the baking paper to the tray to prevent sliding.
  To pipe the macarons, hold the piping tip at an angle to the baking tray and pipe circles about 1 inch (2.5 cm) in diameter.
  Grab the sides of the baking tray and tap it on a hard surface (such as your kitchen bench) 3 to 4 times to remove air bubbles. Refill the piping bag and pipe and tap the second tray of macarons.
  Rest the macarons for 30 minutes before baking, or until the macarons are not sticky or tacky to touch.
  While the macarons are resting preheat the oven to 150 celsius (300 Fahrenheit).
  Place a piped tray in the middle rack of the oven for 16 minutes, rotating the tray at the 8 minute mark. Remove from oven and cool on the tray for a few minutes before removing the baking paper from the tray and allowing the macarons to cool for 30 minutes on a cool surface before placing onto a cooling rack.
  While the macarons are cooling make the ganache. Place the cream in a small saucepan and bring to a boil over a medium heat. Remove from the heat and add the chocolate and leave to sit for a minute. Add the sea salt and whisk to combine. Leave to cool at room temperature until the ganache is a spreadable consistency and not too runny.
  Once completely cooled fill with chocolate ganache and refrigerate, covered, for 24 hours to allow the flavours to fully develop.