On medium-high heat, add the sunflower oil to a large heavy pot (one that has a tight fitting lid). When it begins to smoke slightly, add the beef and brown very well. Do in batches if necessary. Add the salt and pepper as the beef browns. Once browned, remove the beef with a slotted spoon set aside.
Add the onions and sauté for about 5 minutes, until softened. Reduce heat to medium-low, and sprinkle the flour and cook for 2 minutes stirring often. Add the garlic and cook for 1 minute. Add wine and deglaze the pan, scraping any brown bits stuck to the bottom of the pan. The flour will start to thicken the wine as it comes to a simmer. Simmer wine for 5 minutes, and then add the broth, bay leaves, thyme, rosemary, and the beef. Bring back to a gentle simmer, cover and cook on very low for about 1 hour.
Add potatoes, carrots, and celery, and simmer covered for another 30 minutes or until the meat and vegetables are tender. Taste and adjust seasoning. Turn off heat and let sit for 15 minutes before serving. Garnish with the fresh parsley if desired.