2 oz Pisco
1 oz Lime juice
1 oz Simple syrup
1 Egg white
3 dashes Amargo Cucho bitters (Peruvian bitters)

Shake the egg white as hell together with the syrup, pisco and lime juice. Then add ice and shake rigorously for a short period of time. Strain into a coupe glass and add the bitters on top of the foam.