Start by seasoning both sides of your beef with a generous amount of salt. Place the beef into a bowl and cover with lime juice. Cover the bowl and refrigerate for 2 hours.
After 2 hours yank the bowl from your fridge and heat a splash of olive oil in a skillet over medium-high heat. Discard the marinade.
Sear the steak on both sides until the steak is cooked to your liking. Place the steak on a cutting board and let it rest for 10 minutes. After 10 minutes cut it into thin strips. I'll often put the cut steak (and juices) back into the skillet over low heat while I'm preparing the tortillas.
At this point, you can cook your corn tortillas the way you like best. I heated some olive oil in another skillet and fried my tortillas. I allowed them to drain on a paper towel before serving.
Once the tortillas were cooked I spooned in some beef and topped them with diced onion and cilantro.
I can't eat tacos without sliced avocado so I added them for good measure.