Trim fat from brisket and season meat with salt and pepper. Place in baking dish, Cover with onions. Reserve 1/4 cup of beer. Combine remaining beer with brown sugar, bouillon and spices. Pour over meat and cover with foil. Bake at 350 degrees for 3 to 3 1/2 hours or until meat is tender. Remove meat, skim off fat and remove bay leaf. In saucepan cook juices down to 2 cups. Combine reserved beer and flour; Stir into pan juices and cook until thickened. Season to taste with salt and pepper. Slice meat across the grain and serve with gravey.