Pre-heat a heavy frying pan that will hold the steaks in a single layer over medium to medium high heat. Add the oil. Right before you start frying the steaks, season liberally with salt and pepper.
Turn on your ventilation fan. This is going to smoke.
Place the beef in the pan and fry around 3-4 minutes. You want a nice crust on the beef. This should get you to about medium rare. Depends on how thick your steaks are and how hot your pan is. I can't be more precise because I just don't know your specific details.
Flip the steak and cook it another 3 minutes. Remove and let rest around 10 minutes. Check your internal temperature. 125F is rare. 130 is medium rare. Remove the pan from the heat.
After the steak has rested for 10 minutes cut the beef into big bite size chunks.
Return the pan to medium low heat. Keep an eye on it. You don't want your fond to burn. Once it is heated add the garlic and cook around 30 seconds.
Turn the heat up and deglaze the pan with the sauce. Scrape up all that delicious brown gold and stir to get it to dissolve into the sauce.
As soon as you have finished deglazing the pan turn down the heat to low. Taste it. Now start adding the rice wine vinegar. You are looking for a nice balance of acid and savoury. Creep up on it.
When you get to the point you are happy with your sauce (now your vinaigrette really) return the beef to the pan. Heat through gently. You don't want it to cook more. Just warm it up.
To serve spread your greens out on a plate. Top with onions and tomatoes. Drizzle with a bit of vegetable oil. Spoon the beef onto this mixture and drizzle with the sauce. Serve with lime wedges. Plate individually or as a communal appetizer.