Grind the pepper and garlic to a coarse paste along with some water. Mix with amchur powder, salt, turmeric powder and 1 tbsp. oil.
Prick the chicken all over with a fork. Smear this paste all over the chicken pieces and marinate for 5- 6 hours, preferably overnight.
Grease the upper rack of a microwave and place the marinated chicken on it. Pour the leftover marinade over it and grill for 15 minutes on one side.
Flip it over and baste with some oil or the remaining marinade. Grill for 15 minutes more. Let it stand for 5 minutes. Serve hot along with a dash of lime, sliced onion and green chilies.