Heat olive oil in a large pot over medium-high heat.
Add diced beef and brown on all sides. Remove and set aside.
In the same pot, sauté onion, garlic, carrots, and celery until softened.
Sprinkle flour over vegetables and stir to coat (optional, for thickening).
Return beef to the pot. Add beef broth, red wine (if using), thyme, rosemary, salt, and pepper.
Bring to a boil, then reduce heat and simmer for 1 hour, covered, until beef is tender.
Add potatoes in the last 20 minutes of cooking if desired.
Adjust seasoning to taste and serve hot.