To Prepare (Lamb)
Season the lamb with salt and pepper. Sear in half the olive oil in a Dutch oven over high heat. Remove the lamb and discard the drippings.
* Heat the remaining olive oil and butter in the Dutch oven. Add the celery, carrots, onion, garlic, mushrooms and bouquet garni. Saute until the vegetables are tender.
* Return the lamb to the pan. Add the wine, stirring to deglaze. Cook until the liquid is reduced by 2/3. Stir in the tomatoes and chicken stock. Adjust the seasonings. Bring to a boil.
* Bake at 350 degrees for 1 to 1-1/2 hours or until tender, turning the lamb every 30 minutes; discard the bouquet garnish.