Kevin R. Convey
in the Boston Herald offers some tips and advice on grilling an entire fish - a process he says puts more flavor into the end product because you're cooking the bone skin and flesh together, which adds much more flavor than simply grilling a fillet.
After ensuring that your fish is fresh (bright eyes, red gills, firm flesh) and pan dressed, Convey offers up the follow advice on cooking and serving from chef David Kamen:
When it’s time to cook, get the grill good and hot - gas is more convenient, charcoal or wood more flavorful - clean and grease the rods well with an oil-soaked paper towel held in a set of tongs, pat the fish dry, cut three or four diagonal slashes to the bone in each side, then season and oil it to reduce sticking.
DeRego recommends cooking whole fish in part over an indirect flame, which takes longer but is a bit more forgiving than Kamen’s direct-grilling method. But whatever method you choose, turn the fish only once - no pushing, prodding or flipping - and do so by slipping a long spatula under the length of the fish and gently rolling it over.
Kamen recommends 7-10 minutes per side, but urges cooks to check for doneness near the spine with a knife, looking for flesh that is just turning translucent and slightly flaky. More exact is a thermometer reading of 140-145 degrees near the bone. Remove the fish from the grill in the same way you flipped it, and remember that the fish will continue to cook once it’s off the flame.
To serve, run a sharp knife along the spine and belly of the fish, and then cut a line behind the gills and in front of the tail. Use a spatula to carefully remove the fillet, working from top to bottom. Pull the tail up to remove the skeleton, and then lift out the other fillet. To do this cleanly takes some practice, so be patient.