Season the oxtails with salt and pepper on all sides. Set aside.

In a medium pot, heat the oil over medium-high heat. Add the oxtails and sear them on all sides until nicely browned, then set aside.

Add the chopped onion, carrots, celery, and minced garlic to the pot, and cook until tender, stirring occasionally.

Sprinkle the flour into the pot, mixing it until golden brown, then add the tomato paste and combine.

Pour in the red wine, scraping the bottom of the pot to lift flavorful bits.

Add bay leaves, thyme, parsley, and star anise, and let cook for 1-2 minutes.

Pour in the beef broth and combine well.

Return the browned oxtails to the pot, bring to a boil, then reduce heat to low and cover, simmering for about two hours until meat is tender.

Remove bones, shred the meat, and return it to the soup. Let sit before serving.