2 cups cubes and de-seeded chilled watermelon
1/2 cup chilled water
1 1/2 tbsp suger (adjust according to the sweetness of watermelon)
1-2 tbsp lemon juice
mint leaves for garnish(optional)

Blend the above ingredients for 8-10 seconds.
If you want a smooth drink, strain.
Garnish with mint mint leaves and serve chilled.