Cut Charentais melon into quarters, peel and remove seeds. Cut the fruit flesh into pieces of about 3 cm. Put on long skewers and freeze for about 1 hour. In the meantime cut watermelon into slices, peel and remove seeds. Dice the fruit flesh.
Puree in a mixer with some ice cubes and lemon juice. Put deep-frozen skewers into glasses. Distribute the pureed watermelon. Top up with mineral water as desired. Serve decorated with mint