Preheat oven to 400°. Sprinkle steaks with 1¾ teaspoons salt, ¾ teaspoon pepper, and garlic powder. Let stand at room temperature for 30 minutes.
Heat a 14-inch cast-iron baking pan on the stove top over high heat; add 2 tablespoons oil. Carefully swirl pan to coat surface.
Pat steaks dry. Add steaks to pan; cook until browned and a crust forms, about 3 minutes per side. Remove pan from heat; transfer steaks to a plate.
In a large bowl, stir together potatoes, oregano, paprika, remaining 2 tablespoons oil, remaining 1½ teaspoons salt, and remaining ½ teaspoon pepper. Spread onto baking pan.
Bake for 10 minutes. Stir potatoes; add green onion to pan. Bake until potatoes are tender, about 15 minutes more.
Push vegetables to edge of pan; place steaks in middle, and turn once to coat in oil. Bake until a meat thermometer inserted in thickest portion of steaks reads 130° to 135° for medium-rare to medium, 3 to 5 minutes, or until steaks reach desired doneness. Let steaks stand for 10 minutes before serving. Garnish with oregano, if desired.
Recipe by Southern Cast Iron at https://southerncastiron.com/sheet-pan-steak-smoked-paprika-potatoes/