Steps

1. Combine garlic, lime juice, olive oil, and Mexican oregano to make the Carne Asada Marinade. Marinate the steak in the fridge overnight, 12 hours minimum.
2. Preheat the grill to high or preheat the broiler.
3. Generously season both sides of the steak with salt and pepper. Put the steak on the grill or under the broiler, and cook for 5 to 6 minutes on each side for medium-rare.
4. Let it rest on a cutting board for 5 minutes, then slice thinly. For a more tender bite, I recommend cutting the steak against the grain.
5. Warm tortillas on the comal, tuck tortillas into a kitchen towel lined plate as they’re ready to keep them warm.
6. Chop onions, cilantro, and serrano. Mix together in a bowl with fresh lime juice.
7. Slice steak and serve.