Throw the mango, water, basil, green onion, lime juice, chile, and salt into your blender, and blast on high for 20 to 30 seconds until smooth. lime juice, chile, and salt to taste.
Toss the sauce through the jicama, cover the bowl, and transfer to the fridge. Allow the mixture to marinate for about an hour to break down some of the starch.
Serve over a bed of greens, topped with some crushed raw cashews.