One of my favorite cocktail recipes that I collected from my South American adventures over the last few years! Watch out for this one, it's crazy delish and easy to drink!
Add pisco, lime juice, simple syrup and egg white into a shaker and dry-shake (without ice) vigorously.
Add ice and shake again until well-chilled.
Strain into chilled glasses. Garnish with 3 to 5 drops of Angostura bitters. Using a straw, toothpick or similar implement, swirl the bitters into a simple design, if desired. Serve immediately.
Notes
Pisco is a white brandy made from muscat grapes. If you are uncomfortable with raw egg whites, just leave them out.