1
Combine marinade ingredients, garlic through dried crushed chili using 2 tbsp fish sauce and 2 tbsp brown sugar substitute, stirring well to dissolve the sugar. Or use a mini food chopper or processor to combine the ingredients. Slather the marinade over fish, using your hands to ensure all sides are covered. Set in the refrigerator to marinate while you make the fresh relish and heat up the grill.
2
To make the Fresh Relish (optional): Dice the cucumber and lightly chop the coriander, placing both in a bowl. Combine fresh lime juice, 2 tbsp fish sauce, 2 tbsp brown sugar substitute, and chili in a cup, stirring until sugar dissolves. Pour over the cucumber and coriander, stirring well to combine.
3
Brush your grill with a little oil to prevent fish from sticking (if your fillets are very thin or fragile, use a fish cage to grill them, or grill them over a banana leaf). Allow fillets to grill at least 1-2 minutes before turning. Fillets are cooked when they begin to flake and inner flesh is opaque.
4
Serve fish hot from the grill together with steamed rice. If you made the Fresh Relish, give it another stir and serve it alongside the fish. ENJOY!
Serving Suggestion: I've tested this recipe a number of times and now prefer to double the marinade, reserving half as a side sauce or condiment. The reserved sauce can be heated up or served room temperature - it's great drizzled over both fish and rice!