Step 1

Add some Tajín to a shallow small plate. Run a lime wedge around the rims of your serving glasses, then dip the rims lightly in the Tajín.  Set the glasses aside until ready to use.

Step 2

Add the frozen watermelon chunks, lime juice and water to a blender.  Cover and blend until smooth, adding in more water as needed to get the blender going and achieve a thick slushie consistency.

Step 3

Pour the mixture into your serving glasses, top each with a slice of lime for garnish if desired, then serve and enjoy!