Mix together the lemon juice, curry powder, olive oil and Greek yoghurt, add the chicken cubes and toss to coat well. Cover and allow to marinate in the fridge for about 4 hours.
Line the grill tray with a sheet of tin foil. Remove the chicken from the fridge and spread out over the tin foil. Grill the chicken under a medium heat, turning once, till no longer pink in the centre and slightly charred. Remove from the heat and allow to cool slightly.
In a bowl, mix the plain yoghurt with salt and mint to make a simple raita; set aside.
Line a wrap with lettuce leaves then spread over some sliced mango and cooked chicken and drizzle with raita; repeat to assemble the other 3 wraps. Eat immediately fresh or serve raita separately if taken away for a wrapped lunch. Alternatively you can serve over a plate scattered with lettuce leaves or in a pitta bread.
If no fresh mint available mint sauce can be used it not too runny.