Aged Rib Eye with Onion Purée

Name: Aged Rib Eye with Onion Purée
Yield: 4 servings
Ingredients: 1 6 tablespoons unsalted butter, divided; 1 2 medium Vidalia or Maui onions (about 1 1/4 pounds total), very thinly sliced on a mandoline (about 3 packed cups); 1 1/4 cup low-salt chicken stock; 1 1 tablespoon buttermilk; 1 Kosher salt; 1 1 tablespoon vegetable oil; 1 1 28-ounces dry-aged rib-eye steak (about 2" thick), standing at room temperature for 1 hour; 1 Coarse sea salt; 1 Assorted soft herb sprigs (such as tarragon; 1 flat-leaf parsley; 1 and chervil)

From the kitchen of Carly

A thick-cut dry-aged rib eye meets its match in silky onion purée, sweet from long, slow cooking and brightened with buttermilk. The steak's deep crust and tender interior need nothing more than this elegant, buttery onion sauce and fresh herbs scattered on top.

Prep: n/a
Cook: n/a
Total: n/a
Servings: 4
Difficulty: medium

Ingredients

4 servings

16 tablespoons unsalted butter, divided
12 medium Vidalia or Maui onions (about 1 1/4 pounds total), very thinly sliced on a mandoline (about 3 packed cups)
11/4 cup low-salt chicken stock
11 tablespoon buttermilk
1Kosher salt
11 tablespoon vegetable oil
11 28-ounces dry-aged rib-eye steak (about 2" thick), standing at room temperature for 1 hour
1Coarse sea salt
1Assorted soft herb sprigs (such as tarragon
1flat-leaf parsley
1and chervil)

Instructions

Heat 2 tablespoons butter in a 12" heavy skillet over medium-low heat. Add onions and cook, stirring constantly, until translucent (do not brown), 10-12 minutes. Add stock and 3/4 cup water. Bring to a simmer, reduce heat to low, cover, and continue to simmer until onions are falling apart, about 20 minutes. Uncover and stir until onions are almost dry (do not brown), about 5 minutes. Transfer onions to a blender. Add buttermilk and 1 tablespoon water. Purée until smooth. Season with kosher salt.
Preheat oven to 350°F. Arrange a wire rack inside a rimmed baking sheet. Melt 2 tablespoons butter with oil in a large cast-iron skillet or large heavy skillet over medium-high heat. Season steak generously with kosher salt. Cook until a deep brown crust forms, 3-4 minutes per side and 1-2 minutes on edges. Place on prepared rack. Roast until a thermometer inserted into steak registers 115°F, about 40 minutes. (Steak will carry over to medium-rare.) Let rest for 30 minutes.
Melt remaining 2 tablespoons butter in a large skillet over medium-high heat; cook until butter browns, about 2 minutes. Add steak and cook for 30 seconds per side, allowing steak to absorb butter. Cut steak into 4 slices. Place 1 steak slice on each plate and sprinkle with sea salt. Spoon warm onion purée alongside. Scatter herbs over purée.