From here, modified.
Mix:
1 T smoked paprika
1/2 T dried oregano
1/2 T garlic powder
1/2 T onion powder
1 t mustard powder
1/4-1/2 t ground cayenne
1.5 t kosher salt
1/2 t dried thyme
in a small bowl.
Slice
2 boneless skinless chicken breasts (about 1.5 - 2 lb)
in half horizontally. Toss them in a shallow bowl with the spice mix to coat thoroughly.
Heat
2 T veg oil
on medium high in a cast-iron pan.
When it shimmers, put in chicken slices and cook 5 min. Flip, and cook 3 more minutes.
Turn off heat, cover with the wok-lid, and let sit 5 minutes. Remove the lid and let chicken sit 2 more minutes.
Slice on the bias into 1/2-inch pieces; serve promptly.