1. Add cubed melon (about 8 oz) in a blender.
2. Add 1 cup of cold kefir or drinkable yogurt to the melon in the blender.
3. Add the leaves of 3 mint sprigs. Blend until smooth.
4. Add 1/2 cup of sparkling water to the kefir-melon mixture.
5. Add 1 tablespoon lime (or lemon) juice and blend briefly. Pour into 2 large glasses.