Heat half of the oil in a skillet or non-stick pan over medium heat. Add the onions and peppers, and season with salt and pepper. Sauté until onions are translucent and peppers are tender (7-10 minutes). Remove the pan from the heat and set aside.
Season the steak on both sides with chili powder, cumin, salt and pepper.
Add the remaining oil to the pan, then add the steak to the pan. Cook steak on both sides to your desired temperature (see below) using a thermometer.
Remove the steak from the pan and rest for 2-3 minutes before slicing against the grain. Warm the peppers and onions in the pan.
Squeeze the lime juice over the steak, serve with tortilla, peppers, and onions. Garnish with cilantro.