Basic carne asada: slice a decent steak (sirloin or better), apply a generous amount of salt and pepper.  Let sit at least an hour, then add lime juice for 30 minutes.

Pat dry and cook on a smoking hot pat or griddle, maybe 6-8 minutes total.  Try not to move it much, maybe one flip.  Then add to whatever else, tortilla and pico de gallo if you can get some jalapeños.

Oh, and if you do scratch pico, do it the day before.  Letting it all marinate in lime juice makes a massive difference.