½ ounce
triple sec, (we like Combier or Cointreau)
3
sprigs fresh cilantro (optional)
2 dashes
Angostura bitters
Tajín seasoning, for serving
Lime wedge, for serving
Method
In a cocktail shaker, muddle the serrano pepper (reserve one slice for serving) with the lime juice, about 30 seconds. Add tequila, triple sec, cilantro and bitters. Fill the cocktail shaker with ice, cover, and shake vigorously until the outside of the shaker is very cold, about 30 seconds.
Place the Tajín on a small plate. Rub the rim of a rocks glass with the lime wedge, then dip the glass rim into the Tajín to coat. Fill the glass with ice and pour in the margarita. Garnish with the lime wedge and reserved pepper slice. Serve immediately.