01 - Pat beef cubes dry with paper towels and season with salt and black pepper.
02 - Heat 2 tbsp olive oil in a large Dutch oven over medium-high heat. Sear beef in batches until browned on all sides. Set aside browned beef.
03 - Reduce heat to medium. Add remaining 1 tbsp olive oil, diced onion, and minced garlic. Sauté until softened, about 3 minutes.
04 - Stir in tomato paste and cook for 1 minute to deepen flavor.
05 - Sprinkle all-purpose flour over vegetables, stirring constantly to coat evenly.
06 - Pour in red wine if using, scraping up browned bits from the bottom of the pot. Let simmer for 2 minutes.
07 - Add beef broth, dried thyme, dried rosemary, bay leaves, carrots, celery, potatoes, and seared beef with juices. Stir gently and bring to a boil.
08 - Reduce heat to low, cover, and simmer for 2 hours, stirring occasionally, until beef is tender and sauce thickens.
09 - Remove bay leaves. Taste and adjust seasoning with additional salt and pepper if needed.
10 - Serve hot garnished with chopped fresh parsley.