Pistachio biscuit (pistachio sponge)

Beat room temperature egg whites with a dash of cream of tartar (or a few drops of lemon juice) and a third of the sugar on medium speed.

Increase the speed and add the remaining sugar; beat to a stiff-peak meringue, the bird's beak stage.

Add the egg yolks and mix until combined, then fold in the sifted flour and cornstarch.

When the powders are incorporated, add the toasted crushed pistachios and the pistachio paste mixed with oil.

Spread the batter onto a greased rimmed baking tray lined with parchment paper, or any baking pan.

Bake at 330F / 160C for 30 minutes.

Let cool, freeze, and cut into desired shapes.