Steak Tips with Roasted Feta Potatoes

Adjust oven rack to upper-middle position and heat oven to 475 degrees. Line rimmed baking sheet with parchment paper. Toss potatoes with 2 tablespoons oil, 1 teaspoon salt, and 1 teaspoon pepper and arrange in single layer on prepared sheet. Roast potatoes until spotty brown and tender, about 20 minutes. Sprinkle potatoes with feta and scallion greens and continue to bake until cheese is just melted, about 5 minutes.

Meanwhile, pat steak dry with paper towels and season with salt and pepper. Heat remaining 1 tablespoon oil in 12-inch skillet over medium-high heat until just smoking. Add steak and cook until well browned all over and meat registers 125 degrees (for medium-rare), 5 to 7 minutes. Transfer to plate and tent loosely with foil.

Add scallion whites and oregano to now-empty skillet and cook until softened, about 30 seconds. Add vinegar and cook until slightly thickened, about 1 minute. Pour sauce over steak and serve with potatoes.