Put steak in the freezer for a half hour to make it easier to cut. Then cut your steak into 1/2 inch cubes.
Mix your salt, pepper, garlic powder, and juice of one lemon into the steak cubes. If you'd like you can cook one little piece of steak on the stove really quick to see if it's seasoned to your liking.
Preheat your griddle to 300-325 degrees. For me that's medium low on the middle two burners and low on the outside two burner for 10 minutes.
Place down your steak and spread it out thin. You want each piece of steak touching the griddle but also touching each other. Do not leave space in between each piece of steak.
Juices from the fat will start to render out. Push it back into the meat. You are trying to cook all the meat in the rendered fat.
Keep tossing the steak and pushing the fat back into the meat for 15 minutes, or until you no longer see fat coming out.
Once all the fat has rendered out push the steak to one corner to stay warm.
Scrape the griddle then throw down your corn tortillas to warm them up and make them more pliable and less likely to tear. It should only take about a minute per side.
Fill each tortilla with steak, cilantro, onions, salsa and a squeeze of lemon. Enjoy!