To clean the sardines, hold each under water and rub gently with fingertips against the grain of the scales to remove them, split open the abdomen with forefinger, empty it, and pinch off the head. Gently pull back the filets, forcing with fingertips to loosen them from the spinal column, starting at the head end, and break off the bone close to the tail, leaving the filets attached to the tail. Rinse and sponge dry between paper towels.
Marinate the sardines for a couple of hours, turning them gently from time to time in their marinade. Wrap each in 1 or 2 sorrel leaves, placing it in a large gratin dish, the bottom of which has been scattered with the chopped onions—the dish should be just large enough to hold them pressed without forcing side by side. Dribble over the marinade, adding a bit more white wine if the bottom of the baking dish is not completely moistened. Press a sheet of aluminum foil over the surface and cook in a 450° oven for some 12 minutes—or a bit longer—until the liquid has come to a bubbling boil and the sorrel has turned grayish, clinging, film-like, to the form of each sardine. Leave for another 10 minutes or so in a warm but not hot oven (remove the dish, turn off the oven, cool it for a few minutes, and return the dish to the oven, still covered with the foil) to steep, the liquid evaporating a bit more—only a spoonful or so of the cooking juices should remain for each guest.
Copyright © 1974 by Richard Olney. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.