Special equipment: 4 metal or bamboo skewers that have been soaked in water overnight
Preheat a grill to medium-high.
In a large bowl, mix together the mint, ginger, sugar, garam masala, salt, and tamarind water. Add the chicken and mix it well. Cover the bowl and allow to marinate in the refrigerator for 30 minutes to 2 hours.
Thread the chicken onto the 4 skewers. Oil the grill and place the skewers onto it. Grill the skewers, turning frequently and basting with the remaining marinade for about 7 to 8 minutes per side, until the chicken is done and the juices run clear. Cut a piece of chicken open with a small knife to test for doneness.
*Can be found in specialty Asian and Indian markets.