Combine blueberries, sugar and 1/4 cup water in a small saucepan over medium heat. Bring to a gentle simmer, mashing berries with the back of a spoon. Simmer 4–6 minutes until syrupy and berries have broken down. Remove from heat, stir in lemon juice. Let cool slightly, then strain through a fine mesh sieve, pressing solids to extract liquid. Refrigerate until chilled. Makes about 3/4 cup.

Tamarind Puree (optional)

Prepare tamarind puree

Place tamarind pulp in a small bowl and pour 1/2 cup hot water over it. Let sit 10 minutes to soften. Break apart with a spoon, then strain through a fine mesh sieve, pressing to extract the pulp and discard fibers and seeds. If too tart, stir in up to 1 tsp brown sugar to taste. Chill before using.

Cocktail

Rim the glass

Rub a lime wedge around the margarita glass rim. Dip rim into coarse salt or a tamarind-sugar mix (mix 1 tbsp sugar with a pinch of tamarind powder or a smear of tamarind puree and a pinch of salt) to coat. Set glass aside.

Build and shake

In a cocktail shaker, add 2 oz blanco tequila, 0.75 oz prepared tamarind puree (or 3/4 oz tamarind concentrate), 0.5 oz blueberry syrup, 0.5 oz agave nectar, 1 oz fresh lime juice, and 0.5 oz orange liqueur. Fill shaker with ice (about 1 cup) and shake vigorously for 12–15 seconds until well-chilled and slightly frothy.

Strain and serve

Double-strain the mixture into the prepared margarita glass over fresh ice (or serve neat into a chilled coupe). If desired, add a few whole blueberries into the glass for visual contrast.

Garnish

Garnish with a lime wheel on the rim and skewer 4–6 fresh blueberries on a pick and rest on the glass or drop into the drink. Serve immediately.