Cut the flank steak into 4 pieces and then place it in the instant pot sleeve along with 8 cups of water, 1/2 onion, 1/2 green bell pepper, and 1 tbsp sazonador total.
Seal the lid, press the "pressure cook" function, and cook for 40 minutes. Once the 40 minutes are up, remove the flank steak from the instant pot and shred it using two forks. Discard any fat.
Place the shredded flank steak in a bowl and set it aside.
Combine the juice of two limes, garlic, and 2 tsp of sazonador total.
Pour the lime juice over the shredded beef and season with salt and pepper.
Heat about 1/4 cup of vegetable oil over medium-high heat. Add the shredded beef, spread it in a single layer, and fry for 4-5 minutes or until crispy.
While the beef cooks heat some olive oil in a separate skillet over medium heat. Add the sliced onions and cook for 8-10 minutes, stirring frequently. Season with salt.
Serve the vaca frita with the sauteed onions and enjoy!
Notes
Cooking time doesn't include the time it takes for the instant pot to come to pressure.