Preheat the broiler; adjust the rack so that it is about 4 inches from the heat source. Cut 3 or 4 gashes on each side of the fish, from top to bottom. Mix together the oil, wine, salt, pepper, thyme, and fennel in a baking pan large enough to accommodate the fish. Put the fish in the pan and rub it with the oil mixture.
Broil the fish, adjusting the distance between it and the heat source so that it browns evenly but not too quickly. Try to turn the fish only once; total cooking time will be approximately 15 minutes.
When the fish is done, transfer it to a platter. Working quickly, add the olives to the pan and cook on the stove over high heat, stirring, for just a minute, to heat them up and combine them with the pan juices. Spoon or pour the olive sauce over the fish, garnish, and serve with the lemon wedges.
