Using a blender, process the watermelon cubes until they are smooth.

Add jalapeno to it and leave it aside for about 30 to 40 minutes.

In the meantime, make the mint and lime syrup.

Add 1 cup water, 1 cup sugar, zest of 2 limes and mint leaves to a pan.

Bring to a boil and keep stirring until sugar has dissolved. This will take about 2 minutes.

Keep it aside and let it cool.

After 30 minutes, strain the watermelon mixture through a sieve into a pitcher. Discard the jalapenos.

Strain the syrup into the pitcher and add the lime juice to it.

Finally add salt and stir it well.

Serve it cold.