If using a roast, cut the beef into 1-inch chunks.
Then toss the beef chunks in the flour, making sure to cover all sides of the beef with the flour.
In a large soup pot, melt the oil over medium high-heat.
Add the beef and brown the beef on all sides. once the beef has been browned, remove the beef from the pan and set it aside.
Add the onion and the garlic to the pot and sauté for one minute, scraping the bottom of the pot as you stir. You can add a little water to loosen the bits stuck to the bottom of the pot.
Add the mushrooms and sauté for about 5 minutes.
Return the beef to the pot and add the beef stock, Worcestershire sauce, salt, and pepper.
Mix well and bring to a boil. Then reduce heat to medium-low and simmer for 2.5 hours, stirring occasionally.
Add the potatoes, pumpkin, carrots and thyme sprigs. Increase heat to medium. Cook for an additional 30 minutes to 1 hour.
Add salt to taste and serve hot.