Habanero-Hibiscus Sour

Syrup:

Combine sugar, 2 habaneros, and 1/2 cup water in a small saucepan and bring to a boil, stirring until sugar has dissolved. Remove from heat. Halve remaining habanero lengthwise, and stir into syrup along with flowers. Let steep 10 minutes. Strain into a Ball jar or other heatproof container with a lid; let cool completely. Cover and refrigerate until cold. Syrup can be refrigerated up to 1 month. (Makes 1/2 cup.)

Cocktail:

Fill a cocktail shaker halfway with ice. Add pisco, syrup, and lime juice. Shake vigorously 10 seconds; strain evenly into 2 chilled coupe glasses. Add egg whites to shaker. Shake vigorously until very frothy, about 20 seconds; strain evenly into glasses. Top each with a few dashes of bitters; serve immediately.