Place roast in container and cover with wine, water, onion, celery, garlic, spices, salt, pepper and sugar. Marinate for 3 whole days, turning meat daily to allow even distribution of spices and wine.
Remove meat from liquid after 3 days and brown in hot oven (425 degrees). When brown, dredge with flour and make a light roux.
Add the liquid in which the meat was marinated to make gravy. (1/2 cup of tomato puree may be added as well). Reduce oven temperature to 350 degrees and simmer pot roast in the gravy, in an open roaster, until tender (1 1/2 to 2 hours).
Remove pot roast, strain gravy to remove onions and spices before serving.