Preheat the oven to 155'C.
Pass the almonds and icing sugar through a medium sieve to remove any lumps.
Whisk the egg whites with 150g of caster sugar. Whisk until you have a semi-stiff and glossy meringue.
Stir in one third of the dry ingredients. Once incorporated, repeat with the second third and then the final third. Add the food colouring and work the mixture with a spatula until it is smooth, shiny and a dropping consistency.
Fill a piping bag with the macaroon mix and pipe the macaroons onto a lined baking tray. Tap the tray on your work surface to smooth out the tops and remove any large air bubbles. Leave the macaroons to dry for 15 minutes at room temperature. They are ready to cook when the surface is touch-dry. Transfer to the oven and bake for 10-12 minutes. The macaroons are cooked when the top is firm. Remove from the oven and leave to cool for 10 minutes. After 10 minutes, lift the macaroons from the baking parchment and turn them over. Allow to cool thoroughly before filling.
Grate the tonka bean.
Place the milk and grated tonka bean in a saucepan and bring to the boil.
Place the egg yolks, corn flour, cayenne pepper and caster sugar in a bowl and mix together.
Once the milk has come to the boil, begin adding it to the egg yolk mixture a little at a time. Once all of the milk had been incorporated into the egg yolks, return the mixture to the pan and whisk over a medium to high heat for 3-4 minutes, gently bringing it to the boil. Once boiling, pour the liquid into a bowl and set to one side.
Melt the chocolate over simmering water. Stir the melted chocolate into the egg mixture and then chill in the fridge.
Fill half of the macaroon shell with the chocolate and tonka bean cream then top with a second macaroon shell to finish.
«The cayenne pepper in this recipe can be replaced with smoked paprika, freshly chopped chillies or chilli jam.»