Tereré or terere (of Guaraní origin) is an infusion of Yerba Mate, similar to mate but prepared with cold water and ice rather than with hot water, and in a slightly larger vessel.
What you need:
Large Vessel and Cold Water
Sugar or any other sweetener
How to brew it:
Put some Yerba Mate (40-50g) in a large vessel and add cold water to it. (to get a more potent Terere, you can even boil the yerba mate first and then stick it in the fridge to cool it).
Once steeped for 3-4 hours, squeeze 3-4 lemons and add sugar according to taste.
Add mint leaves for garnish.
And that's it!