- Combine green onions, lime juice, fish sauce, sugar, garlic, and chile in a bowl.
- Mix in shredded mango.
- Chill while preparing shrimp.
- Shell and devein shrimp and rinse well; divide into 4 portions.
- Thread 1 portion onto a slender metal skewer.
- Run a second skewer through shrimp ½ to 1 inch from the first skewer, to keep them flat.
- Repeat with remaining shrimp.
- Grill shrimp on a medium hot grill, covered, for about 3 minutes on each side, or until opaque but still a bit moist in the center of thickest parts.
- Place greens on a platter; mound mango mixture onto the greens using a slotted spoon.
- Place shrimp over the mango salad and garnish with lime slices, if desired.