Start off with the potatoes. 20 minutes before your planning on starting the meal clean and slice the potatoes. Add the slices into a bowl of salted cold water.
Drain the water from the potatoes then layer out onto a paper towel. Completely dry both sides as much as you can. Once they are as dry as possible sprinkle on both sides with Cajun seasoning.
Warm a skillet and add oil. Let it come to medium/high heat then add potatoes. Cook on each side 4 minutes depending on your pan and your heat.
While the potatoes cook, chop your onion. Once the potatoes are done remove them from the pan on to a separate plate. Now it's time to add your onion & steak. Cook thin steaks about 2 minutes per side or longer depending on steak cut, size and desired temperature.
Once the steak has cooked take it and cut into thin slices.
Chop lettuce up lettuce and tomatoes. Assemble the lettuce, tomatoes, cheese, potatoes, steak and onion. Enjoy!