In a large skillet, heat the olive oil over medium-high heat. Add the sliced onion and bell pepper, sautéing until softened, about 5 minutes. Stir in the minced garlic and cook for an additional minute until fragrant.

In a slow cooker, place the flank steak. Season with cumin, oregano, paprika, black pepper, and salt. Pour the sautéed vegetables over the steak.

In a separate bowl, mix together the beef broth, orange juice, lime juice, soy sauce, and bay leaf. Pour this mixture over the steak and vegetables in the slow cooker.

Cover and cook on low for 8 hours or on high for 4 hours, until the beef is tender and easily shredded with a fork.

Once cooked, remove the beef from the slow cooker and shred it using two forks. Return the shredded beef to the slow cooker, mixing it with the juices and vegetables.

Serve the shredded beef warm, garnished with fresh cilantro. It pairs well with rice, tortillas, or on a sandwich.