Combine orange juice, lime juice, minced garlic, cumin, oregano, salt, and pepper in a large bowl.

Place the flank steak in the marinade, ensuring it is well-coated. Let it marinate for at least 30 minutes.

Heat 1 tablespoon of olive oil in a skillet over medium-high heat. Sear the flank steak for about 5-7 minutes on each side until browned.

Remove the steak from the skillet and let it rest for about 5 minutes, then shred the beef.

In the same skillet, add the remaining tablespoon of olive oil and sliced onion. Cook until the onion is translucent, about 5 minutes.

Add the shredded beef back into the skillet with the onions and let it cook for an additional 5-10 minutes, allowing the beef to get crispy edges.

Remove from heat and garnish with fresh cilantro.

Serve immediately with rice, black beans, or plantains.