Season the Oxtail generously with salt and pepper.
Heat Olive Oil in a large pot or Dutch oven over medium-high heat. Brown the Oxtail in batches, ensuring not to overcrowd the pot. Set aside.
Add Onion, Carrots, and Celery to the pot and cook until softened, about 5-7 minutes. Add Garlic and cook for another minute. Stir in Tomato Paste and cook for 1 minute more.
Deglaze the pot with Red Wine, scraping up any browned bits from the bottom. Let the wine reduce by half.
Return the Oxtail to the pot. Pour in Beef Broth, add Bay Leaves, Thyme and Rosemary. Bring to a boil, then reduce heat to low, cover, and simmer for 3-4 hours, or until the Oxtail is very tender.
Add Pearl Barley to the soup and continue to simmer for another 30-45 minutes, or until the barley is tender.
Remove Bay Leaves. Season with additional Salt and Pepper to taste. Garnish with Fresh Parsley before serving.
