Add the mezcal, juices, simple syrup, and egg white to an empty cocktail shaker.
Shake the cocktail shaker well, then add ice, and give it a second shake until it is well chilled.
Strain into a cocktail glass and garnish with a lime twist, if desired.
Notes
How to Make Simple Syrup:Mix equal parts sugar and water in a saucepan or microwave safe container, heat on stove or in microwave until the sugar dissolves, stir as needed, then let it cool before using. Keep in the fridge for up 3 weeks. Tips:
Use pasteurized egg whites, either from a carton or pasteurized whole eggs.
For vegan/egg-free option: omit egg white or substitute 2-3 tablespoons of aquafaba (liquid from canned chickpeas) or use a few dashes of a commercial cocktail foamer, if desired.
If you want a sweeter cocktail, increase the amount of simple syrup and/or pineapple juice.
If you want a more tart or sour cocktail, increase the amount of lime juice.