Pistachio macarons with white chocolate pistachio ganache

Bring the pistachios, heavy cream and butter to a simmer in a small pot; add the sugar and cook 5 to 10 minutes until the nuts soften and infuse the cream.

Blend on very high speed until completely smooth; pour some over the white chocolate chips to make the ganache.

Heat water and sugar in a small pot to 250 degrees.

Meanwhile whip half the egg whites in the stand mixer on medium-high until slightly frothy.

Slowly drizzle the 250-degree syrup into the whites and beat to stiff peaks for an Italian meringue.

Sift the pistachio flour and powdered sugar very well, or the macarons turn lumpy.

Mix the sifted dry ingredients with the other half of the egg whites into a pistachio paste.

Add the meringue a third at a time until the batter is like cake batter or 'flowing lava'.

Pipe rounds with a round tip onto a lined baking tray, leaving space between them because the batter is slightly loose; top with reserved pistachio flour.

Let dry 10 to 15 minutes, then bake in a 300 degree oven 10 to 12 minutes.

Cool about 30 minutes before pulling them off the mat.

Flip half the shells, pipe on the ganache and sandwich with the other halves.

variation: mature 24 hours, or up to two days, for a more tender shell as the filling absorbs in.