In a small saucepan, combine 0.5 cup granulated sugar and 0.5 cup water. Stir over medium heat until the sugar fully dissolves and the mixture comes just to a simmer.

Infuse with chilli

Add 0.5 tsp of chopped fresh red chilli (or 0.5 tsp dried chile flakes) to the syrup. Reduce heat to low and gently simmer for 2 minutes to release heat and flavor—do not boil vigorously or it will become bitter.

Cool and strain

Remove the pan from heat and let the syrup steep for 10–15 minutes for stronger heat (shorter for milder). Strain the syrup through a fine mesh sieve to remove solids. Cool to room temperature. Store in a closed jar in the refrigerator for up to 2 weeks.

Cocktail Assembly

Prepare the glass

Rub the lime wedge around the rim of a rocks or margarita glass. Dip the rim into coarse salt or tajín to coat evenly. Set the glass aside.

Make fresh mango purée (if not using store-bought)

Peel and dice 1 small ripe mango (about 1 cup diced). Blend the mango until smooth. Measure 3 oz (about 6 tbsp) of purée for one cocktail. If purée is very thick, loosen with a teaspoon of water.

Combine ingredients in shaker

In a cocktail shaker, add 2 oz blanco tequila, 1 oz triple sec, 3 oz fresh mango purée, 0.75 oz fresh lime juice, 0.5 oz simple syrup, and 0.25 oz chilli-infused syrup. Add about 1 cup of ice.

Shake

Seal the shaker and shake vigorously for 12–15 seconds until the outside of the shaker is very cold (or about 10–12 full shakes). This chills and slightly dilutes the cocktail for balance.

Double strain and serve

Double strain the cocktail into the prepared glass over fresh ice (use a Hawthorne strainer and a fine mesh strainer to catch mango fibers).

Garnish and adjust heat

Garnish with a mango slice on the rim and a thin slice of fresh chilli if you want an extra visual and spicy kick. Taste and, if you want it sweeter, add 0.25 oz more simple syrup; for more heat, stir in 0.1–0.25 oz more chilli syrup (adjust to taste).