Preheat oven to 180°C degrees. Bring a heavy-based large pan to medium heat, add 1 tbsp of oil. Rub roast with salt and pepper. Brown Chuck roast all over, about 10-12 minutes. When the roast is nearly completely browned, tuck the onions, carrots, garlic around the roast and allow vegetables to brown and soften as well. Add stock, worcestershire sauce, and soy and scrape all bits of meat off the bottom. Cover with foil and lid, and place in the oven for 1 hour 30 minutes.
Remove pan from oven, and being very careful of steam, add remaining stock if it appears dry. Cover and place back in oven for another 1 hour and 30 minutes.
Cook polenta according to packet directions. Remove pot roast from oven, add vegetables and cover with lid. Let stand until vegetables are tender, about 10 minutes.
Serve pot roast on top of polenta with carrots, onions, vegetables, pan juices and fresh parsley.