Combine 1 cup water, Worcestershire sauce, and bouquet sauce; brush surface of roast with water mixture. Sprinkle with salt and pepper. Spoon sausage into center of roast. Place a small piece of aluminum foil on each bone end. Place roast, bone end up, in a shallow roasting pan. Pour remaining water mixture and 2 cups water over roast. Insert meat thermometer, being careful not to touch bone or fat.
Bake at 375° for 15 minutes; reduce heat to 325°, and bake 1 hour. Add potatoes to roasting pan, and continue baking 1 hour or until meat thermometer registers 170°. Remove roast and potatoes to a warm serving platter, reserving pan liquid. Let roast stand 10 to 15 minutes before slicing.
Degrease pan liquid; pour into a medium saucepan. Combine flour and remaining 1/2 cup water, stirring until smooth. Pour flour mixture into pan liquid; cook, stirring constantly, until thickened and bubbly. Serve gravy and applesauce with roast.