In a small bowl combine the chili powder, cumin, garlic powder, oregano, paprika, salt, pepper, and cayenne pepper. Mix well.
Rub half of the spice mixture all over the pork and let it sit for 20 minutes.
Meanwhile, heat 1 tablespoons of olive oil in a medium skillet. Add the peppers and onions and saute for 7-8 minutes or until softened.
Heat the other tablespoon of olive oil in a large skillet over medium heat. Add the pork flank steak and cook for 2-3 minutes per side or until cooked through.
Remove from heat and let rest for 2 minutes.
Thinly slice the pork.
Fill the tortillas with sliced pork, peppers, and onions.