If you want a rim, pour the 0.5 tsp Tajín or salted rim mixture onto a small plate. Run a cut grapefruit wedge around the glass lip, then dip the rim into the Tajín to coat evenly. Set the glass aside to dry briefly.

Juice the lime and grapefruit so you have the measured amounts ready. Lightly clap the cilantro between your palms to release aroma; set 1 sprig aside for garnish and pick the remaining leaves for muddling.

Mixing

Muddle and build

In a shaker, add the picked cilantro leaves and the 0.5 oz agave nectar. Gently muddle the cilantro just enough to bruise the leaves and release oils — don't pulverize into bits. Add 2 oz reposado tequila, 0.5 oz blanco tequila, 0.75 oz fresh lime juice, 0.5 oz fresh grapefruit juice, 2 dashes orange bitters, and 0.25 tsp of chili-lime or smoked sea salt.

Shake

Fill the shaker with ice (about 1 cup). Secure the lid and shake vigorously for 12–15 seconds, until the shaker is cold and slightly frosted.

Double-strain

Double-strain the cocktail into the prepared glass (over fresh ice if you prefer it on the rocks) using a fine mesh strainer plus the shaker strainer to catch cilantro bits and ice shards. This gives a clean, herb-scented drink.

Finish & Serve

Garnish with a grapefruit twist or wedge and the reserved cilantro sprig. Optional: pinch a small sprinkle of Tajín on top of the foam or along one side of the drink for an extra chile-lime hit.

Serve immediately. Sip and enjoy the layered notes: warm, oaky reposado, bright citrus, a whisper of grapefruit bitterness, herbaceous cilantro, and a gentle chile-lime finish.