Place the day-old bread in the bowl of a food processor fitted with a metal blade and process into fine crumbs. Combine the pepper and bread crumbs on a plate large enough for dredging the tuna steaks. Allow the tuna to come to room temperature just prior to cooking. This will ensure that the center of the steaks are warmed, not overcooked, and yet not icy cold. Lightly season the steaks with salt, then dredge them in the bread crumb mixture. Coat the tuna uniformly on all sides, pressing the coating in with your fingertips so that it adheres evenly.
Heat the oil in a heavy-bottomed skillet over medium heat until hot enough to brown a sprinkling of test crumbs. Add the fish steaks, being careful not to overcrowd them. Sear to form a crusty exterior on all sides, cooking approximately 3 minutes on each side, turning them to avoid burning. Remember that they will cook to medium rare in about 6 to 8 minutes. A gentle poke with your index finger at the center is a good way to judge doneness: The softer the interior feels, the rarer it is; the firmer, the more well done. When the steaks have cooked to your preference, remove them from the skillet with a slotted spatula and keep them warm--but not hot, or they will overcook.
Add the shallots to the skillet, return to the heat, and quickly saute them until they begin to brown. Deglaze the pan with the wine, allowing it to reduce until nearly dry before adding the stock. Bring to a boil and reduce by half. The entire sauce-making process takes only a few moments. Pour the shallot sauce over the tuna steaks and serve quickly. Accompany with Tomato and Zucchini Gratin
Recipe courtesy of Gourmet Magazine