Preheat your oven to 150°C (300°F) and line two baking sheets with parchment paper.

In a bowl, sift together the almond flour and icing sugar. Set aside.

In a large mixing bowl, beat the egg whites until frothy. Gradually add the granulated sugar while whisking until stiff peaks form.

Gently fold in the pistachio extract and a few drops of green food coloring if using.

Carefully fold the almond flour mixture into the meringue until fully incorporated. The mixture should flow like lava but not be too runny.

Transfer the batter to a piping bag and pipe rounds onto your prepared baking sheets, leaving space in between each macaron.

Let the piped meringues rest at room temperature for 15-30 minutes until a skin forms.

Place the baking sheets in the oven and bake for 15-20 minutes or until the macarons have risen, and you can gently lift them off the parchment without sticking.

Heat the whipping cream over medium heat until hot but not boiling. Pour over chopped white chocolate and let it sit for a minute before stirring until smooth.

Chill until set.

Once cool, pair up macaron shells and pipe ganache onto one shell before sandwiching with another.