It is best done with a whole fish..not too large. Clean them, soak in salty water for a fre minutes. Wrap in paper towel..then sprinke inside with lemon. Outside should be sprayed with a wee bit of oil..no too much or it all gets soggy. get grill very hot and cook five minutes or so a side. Overcooking is the WORST thing..so be careful. Tehn eat the wee buggers...ahhhhhh.
I never buy mackeral that has been filleted, the cut them too thin. Get a whole one...best way is to go to the source ot catch em yourself. We are lucky enough to have a "mackeral and stawberry man". Great fish but an odd taste to the berries.