Peel the mango, roughly cut the pulp from the stone and cut into pieces. Cut the rest of the pulp from the stone and place in a tall container. Add lime and lemon juice, olive oil and water and puree everything with the cutting stick. Season with salt and a pinch of sugar.
Wash rocket, spin dry and place on a plate. Spread the mango and cream cheese on the rocket. Pour the mango dressing over it. Cut the onion into thin strips and spread on the salad.