1. Pat the roast dry with paper towels. Heat the oil in a large pot. Sprinkle seasoning all over the meat. (You may dust the meat with flour, if you would like the stock to thicken up as it cooks).
2. Brown the roast on all sides for several minutes. Remove the roast and put it into the slow cooker on high.
3. Add the onions to the pan and cook for five minutes until translucent. Add the garlic and cook for one minute more. Add the beef stock, bay leaf, Worcester shire sauce, Gravy Master, and the Cream Sherry and bring just to a boil. Pour the stock over the meat in the slow cooker and cover.
4. Cook for one hour on high, then reduce heat to low for 6 hours, or until the meet starts to pull apart with two forks.
5. Add the potatoes and carrots and cook for 60 to 90 minutes more, depending upon your crockpot heat setting, and remaining time you have left before dinner.