Remove any large pieces of fat from the roast. Do not discard. Cut the beef into about 1-inch cubes, and place them in the 4 Quart Slow Cooker.
Add the salt, pepper, and garlic. Place the sliced onion on top of the beef, then position the fat pieces over the onions. Pour in the beef stock.
Cover and place on base. Simmer at setting #3 for about 5 hours or until meat is fork tender but doesn’t fall apart. Discard the fat and onions.
Using a slotted spoon, carefully remove the cubes of beef from the pot and transfer to a bowl. Allow to cool for 30 minutes.
Heat an 9" Sauté Skillet over medium heat. Add 1 teaspoon of the oil, and swirl the pan to coat the bottom.
With paper towels, pat the cubed beef dry, and then add some to the pan. Work in batches to avoid overcrowding the pan. Cook until seared on all sides, tossing occasionally.
Transfer to a serving dish. Add the remaining 1 teaspoon canola oil, and cook the remaining beef.