1. Rub steak seasoning into both sides of the roast.
2. Heat oil in a heavy bottomed pan over medium heat. Once oil is hot, add roast and brown for 4-5 minutes on each side.While the roast browns,
3. Place the beef stock in a medium saucepan and bring to a boil. Allow to boil until stock is reduced by half.
4. Remove from heat then mix in balsamic vinegar and tomato sauce.After the roast is browned on all sides, remove it to a plate.
5. Add the ¼ cup of water to the pan and use a spatula to scrape up all the delicious meaty bits from the bottom.
6. Add the water and browned bits to the sauce mixture.
7. Place onion slices on the bottom of the crockpot. (When I made this I doubled the recipe so my crockpot was full, but if it weren’t, I would also add carrots and maybe even potatoes to the bottom).
8. Place roast on top of the onions, then pour the sauce mixture over. Cook on low for 6-8 hours or until beef is fall apart tender.
9. Remove roast to a plate and cover with foil to keep warm.For the gravy, place 2 cups of the sauce mixture in the crockpot in a small saucepan over medium high heat.
10. Add dissolved cornstarch and bring to a boil. Once boiling, reduce heat to medium and allow sauce to cook, stirring occasionally, until thickened.
11. Serve gravy over meat and onions.