Heat ½ cup of heavy whipping cream in a saucepan over low heat until it simmers, then add 1 cup of unsalted pistachios and let it steep for about 15 minutes.

Strain the mixture and return to heat, adding 6 ounces of finely chopped white chocolate. Stir until smooth and mix in a few drops of gel food coloring.

Chill the ganache in the refrigerator for at least 2 hours until it thickens.

Whip 4 aged egg whites with an electric mixer until soft peaks form, then gradually add ½ cup of granulated sugar, increasing speed to high.

Continue whipping until stiff peaks form, resulting in glossy meringue.

Sift together 1 cup of superfine almond flour, 1 cup of powdered sugar, and ½ cup of pistachio flour into the whipped meringue.

Gently incorporate the dry mixture into the meringue with a rubber spatula, avoiding deflation.

Fold the dry mixture into the meringue until a thick, smooth batter forms, aiming for a flowing consistency.

Transfer the batter into a piping bag and pipe 1.5-inch rounds on lined baking sheets, letting them rest for at least 30 minutes.

Preheat the oven to 315°F (160°C) and bake the macarons for 18-21 minutes, avoiding opening the oven door.

Allow the shells to cool completely before pairing similar-sized ones and piping ganache between them.

Refrigerate the assembled macarons overnight for best flavor development.