1 (2- to 2 1/2-lb) whole snapper, including head and tail, cleaned and
butterflied but not boned by fishmonger, leaving bones attached on one side
1/3 cup plus 1 teaspoon extra-virgin olive oil
3/4 teaspoon salt
6 large garlic cloves
3 1/2 tablespoons red-wine vinegar
Put oven rack in middle position and preheat oven to 400�F.
Rinse fish and pat dry, then rub inside and out with 1 teaspoon oil and sprinkle with salt. Place opened fish, skin side down, in a large shallow baking dish (13 by 9 by 2 1/2 inches) and bake until fish is just cooked through, about 20 minutes (fish will be opaque).
While fish bakes, thinly slice garlic cloves. Heat remaining 1/3 cup oil with garlic in a 10-inch heavy skillet over moderate heat, shaking skillet gently, until garlic is pale golden, about 5 minutes. Remove from heat and carefully pour in vinegar (mixture will splatter), then stir to combine. Pour garlic sauce over fish (mixture may splatter).
Makes 4 servings.