Season beef generously with salt and pepper. Place on a plate. Chill, uncovered, for 2 hours. Remove and let stand 30 minutes. Heat a heavy 12-inch skillet over medium-high heat. To check when hot enough, add a large drop of water (1/8 teaspoon) to the skillet. When it rolls around the pan like a bead of mercury it is ready. This will take 2 to 3 minutes.Advertisement
Remove from heat; add oil. Swirl to coat bottom of skillet. Return to medium-high heat. Add beef. Cook for 5 minutes or until a crust forms (be patient; the beef will release when it's ready to be turned). Turn and cook for 2 to 4 minutes more or until done (135°F).
Remove beef from skillet to a clean plate; cover loosely. Remove skillet from heat. Carefully add wine, miso, and soy sauce (mixture will spatter). Return to heat. Bring to boiling, stirring to scrape up browned bits and whisking to incorporate miso. Remove from heat. Whisk in butter, green onions, and ginger.
Spoon sauce over beef to serve. Sprinkle with sesame seeds.