Have butcher cut a pocket horizontally along one side of brisket, leaving a 1/2 in. Border around three sides. In large saucepan, heat the oil. Add garlic and gook over moderate heat for 30 seconds. Add scallions and cook 2 minutes longer. Transfer to a large bowl. Add spinach to same saucepan and cook until barely wilted and still bright green (about 2 minutes). Set aside to cool slightly, then sqeeze dry. Chop spinach coarsely and squeeze out any remaining liquid. Place spinach in bowl with scallions and garlic. Stir in egg, farfel, salt and pepper. Place 4 yards of kitchen string in a small bowl of water to soak. Cut 2 carrots lengthwise into thin slices. Slice remaining carrots into 1/2 in. Rounds and set aside. Place on half of the thin sliced carrots in the brisket pocket in a layer going against the grain of the meat. Spread spinach stufing on top of carrots and arrange remaining thin carrot slices on top of stuffing. Using the kitchen string, tie the brisket at one inch intervals to secure stuffing. Scatter the sliced onions and remaining carrot rounds over the bottom of the pan. Place brisket on top of vegetables. Season the brisket with salt and pepper. Cook uncovered for 15 minutes at 425 degrees F. in a preheated oven. Pour wine and stock into roasting pan and cover tightly with foil. Reduce oven to 325 degrees F. and cook until the meat is fork tender (3 1/2 to 5 hours). Remove from oven, loosen foil, and let brisket rest for 30 minutes. Meanwhile, strain the liquid from the pan, remove any fat and strain again. If less than 3/4 cup of liquid, add stock or water. Place carrots and onions in food processor, add liquid and puree. Reheat in a small pan. Season to taste. Slice brisket against the grain and serve with sauce on the side. Slices should be thick.