Heat a medium cast-iron skillet over high heat. Brush both sides of steak with oil. Sprinkle with 1 teaspoon salt and 1⁄4 teaspoon pepper.
When skillet begins to smoke, add steak. Cook until steak reaches desired degree of doneness, about 4 minutes per side for medium-rare. Remove steak from pan. Cover with foil, and let stand at least 5 minutes before slicing.
Drizzle green onion with olive oil; sprinkle with 1⁄2 teaspoon salt and 1⁄4 teaspoon pepper. Place in hot skillet; cook until slightly charred and just wilted, about 2 minutes. Remove from skillet. Set aside.
Heat a large nonstick skillet over medium heat. Spray with cooking spray; add eggs and remaining 1⁄4 teaspoon salt and 1⁄4 teaspoon pepper to pan. Cook, stirring constantly, until eggs are justset. Remove from heat. Serve with sliced steak, green onion, and toasted bread.
Recipe by Southern Cast Iron at https://southerncastiron.com/flat-iron-steak-and-eggs/