Rabo de toro is a traditional dish originating from the region of Andalusia, although it's eaten throughout the country. Each restaurant and region has their own recipe, but it's usually made with a combination of oxtail, olive oil, onions, garlic, carrots, celery, paprika, tomatoes, red wine, dry sherry, bay leaves, and parsley.
Once cooked, this slow-braised stew is typically served with fried potatoes on the side. It is believed that rabo de toro dates back to Roman times, when the bull would be killed at a bullfight, and its tail would be braised and enjoyed in celebration.