01 -
Spread mango chunks in a single layer on a parchment-lined sheet pan. Freeze uncovered for at least 2 hours until solid. Alternatively, use store-bought frozen mango straight from the bag.
02 -
Cut one lime into wedges. Use a wedge to wet the outer rim of 4 margarita glasses or goblets. Pour Tajín onto a small flat plate and dip each rim into it to coat evenly. Set aside to dry for 2 to 3 minutes.
03 -
Squeeze the remaining lime halves to collect about 1/3 cup of fresh lime juice. Set aside.
04 -
Add tequila, triple sec, lime juice, sugar, water, frozen mango, and ice to the blender. Blend on high for 30 seconds. Scrape down the sides and blend again for 30 to 45 seconds until completely smooth and thick. If the mixture is too thick to blend, add water 1 tablespoon at a time and blend briefly.
05 -
Spoon about 2 tablespoons of chamoy into each rimmed glass. Use the back of a long spoon to drag it up the inside walls of the glass in a loose swirl.
06 -
Divide the mango slush evenly between the glasses. Garnish each with a tamarind straw and a lime wedge on the rim. Serve immediately.