In a bag, mix lime juice, soy sauce, olive oil, salt and spices. Place the steak in the bag and let it marinate for 15-20 minutes. After 20 minutes, dry the steak and cut it into small strips or cubes.
Fry the beef over medium heat for 7-8 minutes, stirring. Then transfer to a plate. You can add 1 tbsp butter to the pan and fry the corn tortillas for 1 minute on each side over medium heat.
Place beef, diced avocado, red onion and chopped cilantro on tortilla. Sprinkle with additional lime juice and serve. If desired, you can also add tomatoes, corn salsa, and cheese.