Trim fat from roast; place meat in a heavy plastic bag set in a bowl. Combine the wine or tomato juice, tomato paste, sage, bouillon granules, pepper, and garlic. Pour over meat. Close bag and marinate in refrigerator for 6 to 24 hours, turning occasionally. Remove meat from marinade, reserving marinade.
In a kettle or pot, brown the roast on both sides in hot oil. Drain well. Pour reserved marinade over roast. Bring to boiling; reduce heat. Cover and simmer for 1 hour.
Remove a narrow strip of peel from around the center of each new potato. (Or, peel and quarter each medium potato.) Add potatoes, carrots, onions, and celery to meat. Cover and simmer 45 to 60 minutes or until tender, adding some water if necessary. Transfer meat and vegetables to a serving platter; cover to keep warm while preparing gravy.
For gravy, measure pan juices; skim fat. If necessary, add water to equal 1-3/4 cups liquid; return to pan. Combine the 1/2 cup cold water and the flour. Stir into juices. Cook and stir until bubbly. Cook and stir for 1 minute more. Season with salt and pepper. Serve with meat and vegetables. If desired, garnish with additional fresh sage. Makes 8 servings.