In two cups, add 2-3 lime slices and ½ tsp sugar into each and mash together with a muddler. This should take just a few seconds.
In a cocktail shaker, combine cold water and Argentinian Yerba Mate. Shake, shake, shake for about 20-30 seconds.
Fill cups with ice and use a tea strainer to filter the Argentinian Yerba Mate.