Set a large pot over medium high heat on the stovetop, add one tablespoon of cooking oil, then add the cubed beef. Sear the beef until it is well browned on all sides, then remove with a slotted spoon and set aside.
Add an additional tablespoon of oil along with the chopped onions. Saute the onions until tender and turning golden brown, then set aside.
Place the mushrooms in the pot next and cook the sliced mushrooms until tender, then add the minced garlic and cook for an additional minute. Set the mushrooms aside with the beef and onions.
Reduce the heat to medium low and melt butter in the pot, then stir in flour to form a roux. Whisk while cooking for five minutes, or until the butter mixture begins to turn light brown.
Pour red wine into the roux and whisk well to scrape loose any burnt-on bits on the bottom of the pot into the liquid. Then add the beef stock small splashes at a time, whisking to combine, until all of the liquid has been added.
Return the beef, onion, mushrooms, and garlic to the pot along with the Worcestershire sauce, sage, thyme, bay leaves, gnocchi, and black pepper. Simmer the soup for 2 hours, or until the beef is tender.
Stir in heavy cream, then taste for salt and add more if needed. Serve with crusty bread for dipping.