Dutch Oven directions: Add the beef broth and flank steak to a large Dutch oven then add the bay leaves, onion, garlic, cilantro, pepper corns. Cut the steak into pieces 2 or 3 pieces if it won't lay flat. in the broth. Heat on high until it boils and then cover. Turn the heat to low for 1.5 hours until it is fork tender and separates easily. Instant Pot directions: Place the same ingredients into the Instant Pot and cook on high pressure for 40 minutes, allow a natural release for 10 minutes then vent.
While the flank steak is simmering prepare the marinade by adding the lime juice, lemon juice, orange juice, salt, garlic, oregano, cumin and pepper to a bowl and whisk to combine.
Once the flank steak is tender remove it from the broth and place on a cutting board and shred with two forks. You want very think strips of meat separated along the grain. Save the broth from the Dutch oven to cook with the onions later.
Place the shredded beef into a bowl and pour over the marinade and mix to combine. Allow to sit for 30 minutes.
Add the olive oil to a large skillet on medium high heat and fry the beef. Leave all the steak in place until you get very brown crispy edges on the bottom. Once it is crispy you can flip parts of the beef over to fry the other side. You can work in batches if you do not have enough room for all the beef in your skillet.
Add the fried flank steak to a serving platter and cover with foil to keep warm while you cook the onions.
Once all the beef has been fried add 1 cup of the strained beef broth from the Dutch oven to the skillet to deglaze the pan. Stir to remove and the crispy brown bit left in the pan. Add the onions.
Simmer the onions in the broth until tender and most of the broth has cooked off.
Serve the onions over the flank steak. Lime wedges go nicely and also black beans with rice. Add salt to taste.