- 1 1/2pounds red or Yukon gold potatoes (4 or 5), pierced several times
- 1/2tablespoon olive oil
- 1 to 1 1/2 pounds flank steak
- kosher salt and black pepper
- 1/2cup sour cream
- 3 1/2teaspoons fresh lemon juice
- 1teaspoon cider vinegar (optional)
- 2tablespoons finely chopped fresh chives, plus more for serving
- 1 5-ounce bag arugula
- Heat oven to 400° F. Place potatoes on a plate and microwave, uncovered, on high for 12 minutes.
- Meanwhile, heat the oil in an ovenproof skillet over medium-high heat. Season steak with ½ teaspoon salt and ¼ teaspoon pepper.
- Cook steak for 1 minute per side. Transfer to oven and cook to desired doneness, 6 to 8 minutes for medium-rare. Transfer to a cutting board.
- In a bowl, combine the sour cream, lemon juice, vinegar (if desired), 2 tablespoons water, 2 tablespoons chives, and ¼ teaspoon salt.
- Divide the sliced steak, potatoes, and arugula among individual plates. Drizzle the potatoes and arugula with the sour cream mixture and sprinkle with the chives and ¼ teaspoon each salt and pepper.