Preheat your oven to 300°F (150°C).

In a large skillet, heat a tablespoon of olive oil over medium-high heat and sear the beef ribs for about 3-4 minutes each side.

Remove ribs and sauté chopped onions and minced garlic in the same skillet until fragrant, about 2-3 minutes.

Pour in the tomato sauce, chipotle peppers, cumin, paprika, oregano, salt, and pepper, stirring to combine.

Nestle the browned ribs into the mixture, coating them well.

Transfer to the oven and cover with foil, cooking for about 3 hours.

For slow cooker method, place all ingredients in slow cooker and cook on low for 6-8 hours.

Check for doneness; meat should pull away from bone easily. If necessary, add an additional 30 minutes.

Allow the ribs to rest for 10 minutes before serving, adjusting sauce seasoning if needed.