Vegetable-Stuffed Loin of Veal with Sweetbreads - veal sweetbreads

Method

• Soak sweetbreads in a large bowl of ice and cold water in the refrigerator, changing water occasionally (2 or 3 times), at least 8 hours.
• Drain sweetbreads and transfer to a 4-quart heavy saucepan.
• Cover with cold water by 1 inch and add 1 tablespoon salt.
• Bring to a boil, then reduce heat and simmer, uncovered, until sweetbreads plump and feel slightly firmer to the touch, about 3 minutes.
• Drain in a colander and transfer to a bowl of cold water to stop cooking.
• Cut away any fat and pull away as much membrane and connective tissue as possible with a small paring knife without breaking up sweetbreads.
• Arrange sweetbreads in 1 layer in a baking dish, then cover with plastic wrap and top with another baking dish or plate holding weights.
• Chill sweetbreads, weighted, at least 8 hours.
• While sweetbreads chill, blanch pistachios in a small saucepan of boiling water 1 minute, then drain and peel.
• Pat sweetbreads dry and season with salt and pepper.
• Heat oil and 2 tablespoons butter in a deep 12-inch skillet over moderately high heat until foam subsides, then saute half of sweetbreads, turning over once, until golden brown, about 4 minutes total, and transfer to a plate.
• Add 1 tablespoon butter to skillet and saute remaining sweetbreads in same manner, transferring to plate.
• Add remaining 2 tablespoons butter to skillet, then reduce heat to moderate and cook pancetta, stirring occasionally, until beginning to brown, 2 to 3 minutes.
• Add onion, carrot, celery, garlic, bay leaf, and thyme, then reduce heat to moderately low and cook, stirring, until vegetables are softened, 3 to 5 minutes.
• Add Sherry and bring to a boil, then add demi-glace, water, 1/2 teaspoon salt, 1/4 teaspoon pepper, pistachios, and sweetbreads and return to a boil.
• Reduce heat to low, then cover surface of mixture with a buttered round of parchment paper (buttered side down) and simmer sweetbreads, skillet partially covered with lid, until firm but still springy to the touch, 15 to 20 minutes.
• Transfer sweetbreads with a slotted spoon to a bowl and, when cool enough to handle, pull apart into 1- to 1 1/2-inch pieces.
• Ladle cooking liquid through a sieve into a bowl, discarding bay leaf and thyme, and reserve.
• Reserve vegetables in another bowl for sauce and stuffing.
• Cook spinach in a large pot of boiling salted water , uncovered, until wilted, about 20 seconds, then drain in colander.
• Transfer spinach to a bowl of cold water to stop cooking and drain again, squeezing handfuls of spinach to remove excess liquid.
• Chop spinach and stir into reserved vegetables along with 1/4 teaspoon salt, 1/4 teaspoon pepper, and 1/8 teaspoon nutmeg.
• Put oven rack in middle position and preheat oven to 400F.
• Make a hole for stuffing that runs lengthwise through veal: Beginning in middle of 1 end of roast, insert a sharp long thin knife lengthwise toward center, then repeat at opposite end of loin to complete an incision running through middle.
• Open up incision with your fingers, working from both ends, to create a 1 1/2-inch-wide opening.
• Pack loin with all but 2 tablespoons vegetable stuffing, pushing from both ends toward center.
• Tie veal roast with kitchen string at 1-inch intervals along entire length of roast.
• Pat veal dry and season generously with salt and pepper.
• Heat oil in an ovenproof 12-inch heavy skillet over high heat until just smoking, then brown veal, turning with tongs, about 5 minutes.
• Transfer skillet to oven and roast veal until thermometer inserted diagonally 2 inches into meat (do not touch stuffing) registers 150F, 45 to 50 minutes for veal; about 40 minutes for pork.
• Transfer roast with tongs to a platter and let stand 20 minutes.
• Skim fat from sweetbread cooking liquid and bring liquid to a boil in a 2 1/2-quart heavy saucepan.
• Stir in remaining 2 tablespoons vegetables, remaining 1/4 teaspoon salt, remaining 1/4 teaspoon pepper, and remaining 1/4 teaspoon nutmeg.
• Add sweetbreads along with any veal juices accumulated on platter and simmer until just heated through.
• Remove from heat and keep warm, covered.
• Discard string, then cut veal into 1-inch-thick slices and serve with sweetbreads and some sauce.
• Serve remaining sauce on the side.