Whisk the flour with 1/2 tsp seasoned salt in a large bowl.
Toss the cubed beef with the flour mixture until evenly coated.
Heat 1 tbsp of olive oil in a large skillet over medium-high heat.
Add the dredged beef to the hot skillet and sear on each side until evenly browned (about 30-45 seconds per side). Work in batches until all the beef is seared and transfer the meat to the slow cooker. Add a little extra oil, or use olive oil cooking spray, if needed.
Add the remaining olive oil to the skillet and reduce the heat to medium.
Add the onions and garlic and cook for 2 more minutes, stirring often, until lightly golden. Pour the onions and garlic over the beef in the crockpot.
Whisk together: wine, tomato paste, and the Worcestershire sauce and pour on top of the onions and beef.
Add the remaining ingredients to the slow cooker and pour the stock over the top.
Cook on High for 4 hours, or 8 hours on Low. The meat should be fork tender when done.