Place the chocolate in a bowl that is big enough to fit the cream in to. Place the cream in a saucepan and bring it to the boil. Pour the boiling cream onto the chocolate and stir until the chocolate is fully combined with the cream and melted.
Add the lemon juice to the ganache and stir fully, then add the butter until it's fully mixed. Leave the ganache somewhere to cool to room temperature, don't be tempted to put the ganache in the fridge as you're going to want to pipe it later.
Put the blueberry puree, blueberries and 40g sugar in a saucepan and bring to the boil.
Combine the pectin with 20g of the sugar and mix thoroughly, add this to the fruit, along with the lemon juice and keep stirring until the fruit reaches 104C.
Pour the confiture into two sterilised jars and leave to cool.
Preheat the oven to 170C Fan and line four baking trays with baking parchment. You can use these macaron sheets as a guide when piping out 4cm circles.
Add the water and sugar to a pan and stir over a medium heat until the sugar dissolves.
Put half of the egg whites into a stand mixer and whisk them on a medium speed until frothy.
Bring the syrup to a boil and heat until it reaches 118 degrees.
Pour the syrup in a slow steady stream into the egg whites as they are being whipped on a high speed. Keep whipping until the meringue forms a stiff peak, about 5mins.
Grind the ground almonds and icing sugar together in a food processor and then sift them into a clean bowl, add the freeze-dried blueberry powder too.
Add the remaining egg whites to this mix and beat it, until it forms a paste.
Add a third of the meringue to the almond paste and beat it in thoroughly.
Fold through the remaining meringue, ensure the ingredients are mixed thoroughly.
Put the macaron mix into a piping bag and pipe out 48 macarons.
Tap the bottom of the tray to remove any bumps or air pockets, then put the macarons in the oven for 12-14 mins per tray. Turn the trays halfway through cooking to ensure an even bake.
Let the cooked macarons cool completely before trying to remove them from the tray.
Pair up similar shaped macaron shells. With your chocolate ganache in a piping bag fitted with a 1cm straight nozzle, pipe rings of ganache around the outside of the shell. Take some of the confiture and spoon a small blob inside the ring that you have piped.
Place a macaron on top and sandwich them together. Leave for at least 20mins or overnight if possible as the macarons will taste even better when they soften a little.