Season the steak with 1 teaspoon salt and ¼ teaspoon pepper. Heat the oil in a large skillet over medium-high heat and cook the steak to the desired doneness, 2 to 3 minutes per side for medium-rare; slice.
Add the pineapple and chili to the skillet and cook, tossing frequently, until tender, 6 to 8 minutes.
Dividing evenly, top the tortillas with the steak and pineapple. Serve with the cilantro and lime wedges.