In a large, shallow ceramic or earthenware baking dish, combine the olive oil, lemon juice, herbs, salt, and pepper. Pat the fish dry with paper towels and add to the marinade, turning to coat all sides evenly. Cover with plastic wrap and marinate in the refrigerator for 1 to 2 hours. Preheat the oven to 375 degrees. Remove the fish from the marinade. Lay out 3 or 4 vine leaves on the counter, overlapping them to form a large, sturdy wrapper. Place a few slices of fennel in the center. Place a piece of fish on top and scatter a few more slices of fennel on top of it. Top the fennel with 1 slice of lemon and 1/2 tablespoon of the butter. Wrap the fish in the vine leaves and lay it, seam side down, in an ovenproof baking dish. Repeat with the remaining fish. Bake for about 30 minutes, until the fish is opaque (you can peek to make sure they are done). Garnish each package with some of the diced tomato. Serve immediately and let the diners unwrap their own fish. Pass a small cruet of extra virgin oil for drizzling.
c.1997, M.S. Milliken & S. Feniger, all rights reserved