Ingredients

  • 1 (4-lb.) New York strip roast, preferably prime, untied
  • Kosher salt, freshly ground pepper
  • 6 garlic cloves, finely grated
  • 3 Tbsp. finely chopped rosemary
  • 5 Tbsp. extra-virgin olive oil, divided
  • 1/2 cup plain whole-milk Greek yogurt
  • 1/2 cup sour cream
  • 2 Tbsp. prepared horseradish
  • 1/2 tsp. finely grated lemon zest
  • Warm rolls and cornichons (for serving)

Method

  • Lightly score fat cap of roast, spacing cuts about 3/4" apart, with a sharp knife, being careful not to slice into the flesh. Season roast generously on all sides with salt and pepper. Mix garlic, rosemary, and 3 Tbsp. oil in a small bowl and rub all over roast. Loosely cover with plastic wrap and chill at least 12 hours and up to 2 days.
  • Preheat oven to 200°F. Place roast on a wire rack set inside a large rimmed baking sheet. Roast until an instant-read thermometer inserted into the thickest part of meat registers 118°F-120°F for medium-rare, about 2 1/2 hours. Let rest 1 hour (internal temperature will continue to climb to 125°F-130°F).
  • Mix together yogurt, sour cream, horseradish, and lemon zest in a small bowl; season sauce with salt.
  • Heat remaining 2 Tbsp. oil in a large skillet over medium. Cook roast just until browned, about 2 minutes per side. Transfer to a cutting board and thinly slice. Serve with horseradish sauce, rolls, and cornichons.
  • Beef can be roasted and browned 3 days ahead. Cover and chill. Let sit at room temperature 1-2 hours before serving.