How to Make It
Combine five-spice powder, brown sugar, salt, garlic powder, and ground red pepper in a small bowl. Rub spice mixture over both sides of flank steak.
Heat a large cast-iron skillet over medium-high. Add olive oil to pan; swirl to coat. Add steak to pan; cook 4 minutes on each side or until desired degree of doneness. Remove steak from pan; let stand 5 to 10 minutes. Cut steak across the grain into thin slices.