Wash the fish and pat dry.Slice though the middle and cube into apprx 2 inch pieces.
Chop up the coriander and mint.In a wet spice grinder or any food processor combine all the chutney ingredients except lemon juice and blend.Add a little more water if required.
In a ziplock bag take about 4-5 tbsp of the Chutney and the fish and give it a good mix.Save the remaining chutney.
Refrigerate the fish for two hours.Add the lemon juice a few minutes before grilling.
Preheat the grill.
Arrange the fish on skewers alternating each fish and grill on medium for about 6 minutes on each side.
Serve hot with the reserved chutney.
