Season the oxtail with salt and pepper, then brown it in olive oil in a large, heavy-bottomed pot. Remove the browned oxtail and set it aside.

In the same pot, sauté the chopped onion, bell pepper, and minced garlic until they are softened and fragrant.

Add the crushed tomatoes, red wine, beef broth, bay leaves, cumin, oregano, and smoked paprika to the pot, bringing the mixture to a gentle simmer.

Return the browned oxtail to the pot, ensuring it is submerged in the liquid. Cover the pot and braise over low heat for 2.5 to 3 hours, or until the oxtail is very tender and easily pulls from the bone.

If using, add the cubed potatoes and sliced carrots during the last 30-45 minutes of cooking, allowing them to soften.

Adjust the seasoning of the stew as needed, then serve hot, garnished with fresh parsley if desired.