In a large pot or Dutch oven, heat the olive oil over medium-high heat. Add the beef cubes and brown them on all sides, about 5-7 minutes. Remove the beef and set aside.
In the same pot, add the chopped onion and garlic. Sauté until the onion is translucent, about 3-4 minutes.
Stir in the tomato paste, Worcestershire sauce, thyme, and rosemary. Cook for another minute until fragrant.
Return the browned beef to the pot and pour in the beef broth. Bring to a boil, then reduce the heat to low and cover. Let it simmer for 1.5 hours.
After 1.5 hours, add the carrots, potatoes, and mushrooms to the pot. Season with salt and pepper. Cover and simmer for an additional 30-45 minutes, or until the vegetables are tender.
If you prefer a thicker stew, mix the flour with a little water to create a slurry and stir it into the stew during the last 10 minutes of cooking.
Taste and adjust seasoning if necessary. Serve hot, garnished with fresh parsley.