Place the mixture in a piping bag and tie a knot in the top. Hold the knot between your thumb and forefinger and squeeze the piping bag from the top. Stick the baking parchment to the baking tray a little bit of the macaroon mix and then pipe the macaroons on to the tray. Gently drop the tray on to your work surface to remove any air bubbles and then leave to rest for 10-15 minutes at room temperature. The macaroons are ready to cook when they no longer stick to your finger when touched.