Heat broiler. Mix chili powder, garlic salt, red pepper, cumin in bowl. Toss potatoes, 3 tablespoons oil, scallions, 2 teaspoons spice mixture in a bowl. Place on baking sheet.
Brush both sides of meat with remaining 2 tablespoons oil. Rub remaining spice mixture over steak.
Preheat oven to 350 degrees F.
Cook potatoes on baking sheet on lowest rack in oven 12 minutes, turning halfway through. At same time, broil meat 4 inches from heat 4 to 5 minutes. Turn meat over. Broil 6 minutes (internal temperature 145 degrees F for medium-rare). Remove the meat from oven; let stand 5 minutes.
While meat is resting, place potatoes under broiler for 3 to 4 minutes or until browned and crispy.
Thinly slice meat on angle. Serve with seasoned fries.