1 each 4-5 lb. duck
1/4 cup plus 1 tbls. unsalted butter, room temperature
1 tbls. vegetable oil
Preheat oven to 400 degrees. Place chicken necks, onion and shallots in large ovenproof saucepan or dutch oven. Roast until bones are brown, approximately 30 minutes. Remove from oven. Add peppercorns and thyme. Over medium high heat, add wine and vinegar. Boil until liquid is thick, about 10 minutes. Add stock and 2 cups berries. Bring to boil. Simmer until reduced to 1 cup. Strain into medium saucepan, pressing solids to extract flavors. Refrigerate until chilled. Can be made 4 days in advance. Skim fat from sauce and bring to boil. Simmer 20 minutes until sauce is reduced to 3/4 cup. When ready to serve, return sauce to a simmer. Whisk in 1/4 cup butter. Remove from heat. Add remaining berries.
To prepare duck, preheat oven to 500 degrees. Pat duck dry and season with salt and pepper. Place 1 tbls. butter and vegetable oil in roasting pan. Place in oven to melt butter. Add duck, breast side down. Roast 25 minutes. Turn and bake another 45 minutes at 400 degrees. Carve duck and serve with sauce.