In a bowl, mix the flour, salt, black pepper, and garlic powder. Dredge the beef pieces in the flour mixture, shaking off the excess.

Heat 1½ tablespoons of olive oil in a heavy pot or skillet over medium heat. Brown the beef on both sides in batches to avoid overcrowding the pot. Add more oil if needed.

Place the seared beef in the crockpot.

Pour in the beef broth, French onion soup, Worcestershire sauce, and bay leaves. Cover and cook on high heat.

In the same pot, add 1 tablespoon of olive oil over medium heat. Add the onions and cook for 3-4 minutes.

Then add the mushrooms and cook until the onions are soft and the mushrooms are browned.

Reduce the heat to low and add the garlic and Italian seasoning. Cook for 1 minute while stirring.

Scrape the bottom of the pot to remove any brown bits, using 1-2 tablespoons of beef broth to help loosen these bits if necessary.

Add the cooked vegetables to the crockpot. Cover and cook on high for 2-3 hours or on low for 4-5 hours.

Mix the cornstarch with the reserved beef broth and stir it into the crockpot. Cover and cook on high for 30 minutes, or until the gravy thickens.