In a small bowl, whisk together spices, then stir in the oil.
Rub half the spice mixture on one side of the flank steak.
Flip over and rub the rest of the spice mixture on the other side.
Whisk together the orange juice, lime juice, lemon juice, soy sauce, and vinegar.
Grease a crockpot and pour in half of the juice mixture.
Place the steak in the crockpot and pour the rest of the juice over the top.
Cover and cook on LOW for 6 hours.
Once cooked, remove steak from crockpot and let sit for 5-10 minutes.
Using a serrated knife, thinly slice the steak against the grain.
Gently place steak back in crockpot and mix with juices.
Serve with corn tortillas, pico de gallo, avocado, and cotija!
Take 5 seconds to . We greatly appreciate it!