We eat all day at the rio, and there are many ways to make Mojarra (tilapia), but this is my favorite, so vsvevg. Do use a wood fire and banana leaves to wrap the fish when you can.
A whole fish, scaled and gutted
Banana leaves, or aluminum foil
Salt the fish inside and out stuff in a slice of onion, tomato, chili and epazote, squeeze on some lime, and place in foil packet, then stick in some low coals. Turn it about a bit it will take about ten minutes, depending on the size of your fish and the heat of your coals, open with caution and eat it out of its packet with some tortillas warmed in the ashes.