- Preheat oven to 325°F (165°C). 
- Season oxtails generously with salt and pepper. Heat oil in a large Dutch oven, then sear oxtails on all sides until browned. Remove and set aside. 
- In the same pot, sauté onions, carrots, celery, and garlic until softened. Stir in tomato paste and cook for 1–2 minutes. 
- Pour in red wine (if using) and scrape up browned bits from the bottom. Simmer for 3 minutes. 
- Add beef broth, soy sauce, Worcestershire, thyme, and bay leaves. Return oxtails to the pot. 
- Cover tightly with a lid and braise in the oven for 2.5–3 hours, until the meat is tender and falling off the bone. 
- Remove bay leaves and thyme sprigs. Adjust seasoning with salt and pepper. 
👉 Serve hot over mashed potatoes, rice, or with crusty bread to soak up the rich sauce.
