For the Stuffed Saddle of Lamb :
1.Warm 1 tablespoon of the olive oil in a large sauté pan over medium-high heat. Add the onion and cook, while stirring, until tender but no color. Add the chanterelles and cook for 3 minutes. Add the Swiss chard and garlic, season with salt and cook, while stirring, until tender, about 5 minutes.
Add the tomato confit and pine nuts and toss all the ingredients together. Season with salt and pepper; cool. When the vegetables are cool enough to handle, squeeze until all the excess water is removed.


2.Center a rack in the oven and preheat the oven to 350°F.


3. Spread the lamb saddle on a work surface and butterfly to a 1-inch thickness. Season both sides with salt and pepper. Spoon the Swiss chard stuffing down the length of the saddle in a compact log, then roll the meat up tightly around the stuffing. Tie the lamb at 1-inch intervals with kitchen twine.


4. Warm the remaining 5 tablespoons oil in a roasting pan over medium-high heat. When the oil is hot, add the saddle to the pan and sear until golden brown, 8 to 10 minutes, turning the saddle as needed. Remove the saddle from the pan, wrap in aluminum foil and return to the roasting pan. Add the butter to the pan, slide the pan into the oven, and roast for 8 minutes, basting occasionally.
Give the saddle a half-turn and roast for 7 minutes more. The internal temperature of the saddle should reach 150°F on an instant read thermometer when done. Transfer the lamb to a warm plate and let rest for 7 minutes. While the lamb is roasting, prepare the Vegetables and Sauce.




For the Vegetables :
1. Put a pot of salted water up to boil. Plunge the asparagus into the boiling water and cook at a steady simmer until it can be pierced easily with the tip of a knife, 3 to 4 minutes for regular asparagus and 6 to 7 minutes for jumbo.
Gently lift the asparagus out of the pot and hold under cold running water to stop the cooking and set the color. When cool, pat dry between kitchen towels. Cut each stalk in half on the diagonal.


2. Melt the butter over medium-high heat and cook to a light golden brown. Reduce the heat to medium. Add the potatoes and rosemary and season with salt and pepper. Cook for 10 minutes, while stirring and basting the potatoes. Add the carrots, and cook for 10 minutes, while stirring and basting the vegetables.
Add the mushrooms and cook until the vegetables are tender, about 3 minutes. Toss in the asparagus until warm. Taste and season with salt and pepper, if necessary.




For the Sauce :
Warm the olive oil in a large sauté pan over high heat. Add the bones and roast for 20 minutes, while stirring. Add the tomatoes, carrot, garlic, bouquet garni, rosemary,and bay leaf and cook for 7 minutes.

Deglaze with the white wine and cook until the liquid in the pan has almost evaporated. Add the beef stock and reduce by half. Strain through a fine-mesh sieve. Return the strained sauce to the pan and stir in the butter until melted. Season with salt and pepper.

To Serve: Remove the string from the saddle and cut into 8 slices. Divide the vegetables among four warm dinner plates. Place 2 stuffed saddle slices on top of the vegetables. Spoon the sauce around.