Mackerel Tuna (Ikan Tongkol) is a rather cheap fish (RM11/kg) to buy when compared to the grouper, snapper and the like (RM53/kg). It can be bought really fresh from Kuala Lumpur's hypermarket. I can't vouch for other types. Mine was bought from Tesco.
Get the workers to de-gut it and then have it halved along the bone. Leave the head on as there is quite some meat on its neck!
Marinade ingredients as per kilogram of fish. My fish was 1.2kg. Adjust to suit your taste:
Meat can be adapted for tuna and other pelagic fishes.
6 tablespoon premium soy sauce (try teriyaki or Worcestershire sauces)
4 tablespoon lime or lemon juice
Some oil to coat the fish adequately
1 sachet of brown sugar (8g)
1 teaspoon ground black pepper
2 cloves garlic
Combine and put the marinade and fish into a zip lock bag. Make sure you roll to bag to get the air out. This is get the marinade to coat properly.
Grilled in oven at 210 Celsius for 20 minutes turning over at 10 minutes. Shorten the time if the meat comes out too hard.
Great fish steak! These fishes have great texture and chewing it is half the eating fun.
Check this site for reference.