Rub the rim of a chilled rocks glass with a lime wedge, dip it in chili-lime seasoning, and fill the glass with ice.
Muddle 1 slice of deseeded red jalapeño and 3 sprigs of cilantro in a cocktail shaker. Add 45ml of blanco tequila, 22.5ml of triple sec, 22.5ml of fresh lime juice, and 5ml of agave syrup.
Fill with ice, shake until cold, and double strain into the glass. Garnish with a lime wedge.
