First, we’ve got some prep work to knock out.
Set yourself up with a nice, clean fish. If you’re buying it from the local monger, look for glassy eyes and nice red gills for the freshest fish in the case.
Make sure the fish fits nicely on the grate…either inside on a grill or a grate over an open flame fire pit.
The Mahi has been cleaned (guts removed), fins and gills removed. Everything else is intact, skin on.
Lay the fish on a piece of aluminum foil that’s large enough to comfortably hold the fish. Tear off a 2nd piece of foil about the same size and set it off to the side.
On either side, depending on the size of the fish, make 3 or 4 “scoring” cuts across the body about an inch long and 1/8 inch deep between the spine and belly area. This helps get a nice, even cook across the fish.
Lightly sprinkle the outside of the fish with your favorite salt.
Prep some olive oil by adding garlic and thyme to it, then drizzle over both sides and baste the inside of the fish.
Add your favorite herbs to the outside and stuff a few inside. Thyme sprigs or tarragon make an excellent flavoring.
Add a few slices of lemon to the outside and inside. Not too much, just 4-6 slices positioned around the outside and inside.
Lay the 2nd piece of foil over the fish and “crimp” the edges of the lower piece and upper piece together. Actually, this style of wrapping is reminiscent of an old French style called “en papillote” where the fish is wrapped in paper.
Essentially, we’re keeping the juices inside the wrap and steaming the fish.
Get the grill heated up at about medium flame. If you’re over an open pit, keep the grate about 10-12 inches above the fire.