Step 1

In a cocktail shaker or glass, muddle the cilantro, lime juice and slice of serrano.

Step 2

Fill the shaker with ice and pour in the tequila, pineapple juice and a light drizzle of agave nectar (optional). Shake well, and strain the mixture over ice in a cocktail glass.

Step 3

Garnish minimally with a lime round, or get fancy with a slice of pineapple and sprig on cilantro on a cocktail pick.