Preheat oven to 160C (325F). Combine salt, ras al hanut, and pepper. Rub seasoning on both sides of the meat.
In large roasting pan, arrange half of onions and garlic. Set roast on top of the onion mixture. Top with remaining onions, garlic, and red wine. Cover pan tightly with foil. Cook for 2-1/2 to 2-3/4 hours, or until pot roast is tender.
Remove pot roast to serving platter; keep warm.
Skim fat from pan juices and onion mixture. Carve pot roast into thin slices. Spoon onion mixture over pot roast. Garnish with parsley, if desired.