
In a large pot or caldero, heat oil over medium-high heat. Sprinkle oxtail with salt and pepper. Add meat to the pot and brown on all sides. Add water and bring to a boil. Lower the heat to medium-low and simmer until tender, about 1 and a half hours, checking and adding more water as needed.
When meat is tender, add adobo, oregano, crushed red pepper, garlic, onion, peppers, carrots, tomato sauce, and olives. Mix to combine.
Let simmer until all vegetables become tender and flavors combine, about 10 to 15 minutes.
Serve warm with white rice and avocado.