Hanger Steak with Green-Garlic Sauce

INGREDIENTS

• 2 hanger steaks or 1 skirt steak (1 1/2 lbs. total)
• 1/2 teaspoon kosher salt, divided
• 1/2 teaspoon pepper, divided
• 1 tablespoon olive oil
• 3 tablespoons butter, divided
• 1 cup chopped green garlic* or green onions
• 1 tablespoon minced garlic
• 1/2 cup reduced-sodium beef broth
• 1/2 cup dry white wine
• 1 tablespoon sherry vinegar