Blend the vinegar, garlic, ginger, salt, cayenne, coriander, cumin and oil in a blender until you have a thick paste. Brush the fish chunks with the mixture to coat evenly and place in a shallow dish; pour the remaining marinade over the fish. Allow to marinate in refrigerator at least 4 hours.
Preheat the grill. Arrange the marinated fish in a grill-safe dish, reserving the marinade.
Cook the fish under the preheated grill on the oven's centre rack for 10 minutes; turn the fish and brush with reserved marinade. Continue cooking until the fish flakes easily with a fork, about 7 minutes more. Serve hot.