Rub olive oil generously inside and on the outside of the fish. Wash and dry your hands, then measure out 1-2 tablespoons of salt, and using one hand to hold the fish open, use the other dry hand to sprinkle in salt.
Stuff a few sprigs of fresh herbs into the cavity.
Slice half the lemon into rounds and divide the slices between the fish, placing in the cavity on top of the herbs. Add more herbs, if desired.
If using foil, add some nonstick spray, then place fish on top. (You can also lay the fish on a bed of herbs – fennel fronds work well for this.) Close up foil around the fish, leaving a small “funnel” in the middle to allow steam to escape.
If not using foil, wet a paper towel with oil and, using tongs, rub your (clean!) grill grate with the oil, and place fish directly on grate.
Grill for approximately 5 minutes per side, until fish unsticks from grate.
To flip the fish, use a large spatula and wiggle it slowly under the fish to help prevent tearing.
The fish is done when the flesh is easily pierced by a skewer or fork.
To serve, squeeze the juice from the other half of the lemon over the top.