Wagyu Steak Frites Recipe

Temper and season

Remove the 12 oz Wagyu strip from the refrigerator 45–60 minutes before cooking and leave loosely covered at room temperature. Pat dry with paper towels. Generously season both sides with kosher salt (use about 1 tablespoon total) and freshly ground black pepper (about 1 teaspoon).

Preheat and sear

Heat a heavy cast-iron skillet over medium-high heat until very hot (about 5 minutes). Add 1 tablespoon neutral oil and swirl to coat. Place the steak in the pan away from you and sear undisturbed for 2–3 minutes until a deep brown crust forms.

Baste and finish

Flip the steak and immediately add 1 tablespoon unsalted butter, the crushed garlic cloves and thyme sprigs to the pan. Tilt the pan and spoon the melted butter over the steak continuously (baste) for 1–2 minutes while cooking to your target doneness (for 12 oz Wagyu NY strip: aim for 125–128°F / 52–53°C for medium-rare; total cook time after flipping typically 2–4 minutes depending on thickness). Remove steak to a cutting board and loosely tent with foil. Rest for 8–10 minutes before slicing.

Prep potatoes

Peel (optional) and cut russet potatoes into 1/3–1/2 inch batons. Rinse under cold water until water runs clear to remove starch, then place in a bowl of cold water and refrigerate for at least 30 minutes (or up to 2 hours). Drain and pat completely dry with clean kitchen towels or paper towels.

First fry (blanch)

In a heavy pot or deep fryer, heat beef tallow to 300°F (150°C). Fry the potato batons in batches for 4–6 minutes until soft but not colored. Remove and drain on a wire rack or paper towels. Let cool 10 minutes.

Second fry (crisp)

Increase tallow temperature to 375°F (190°C). Fry the blanched fries in batches until deep golden and crisp, about 2–3 minutes. Remove and drain briefly on paper towels, then season immediately with 1 teaspoon kosher salt and 1 teaspoon freshly ground black pepper. Toss with 2 tablespoons chopped parsley if using. Keep warm in a low oven (200°F / 95°C) on a rack while finishing steak and sauce.

Make aioli

In a medium bowl combine 1 cup mayonnaise, 2 tablespoons fresh lemon juice, 1 teaspoon lemon zest, 2 tablespoons finely chopped chives, 1 teaspoon Dijon mustard, and 1 very finely minced garlic clove. Whisk until smooth. Season with 1 teaspoon kosher salt and 1 teaspoon freshly ground black pepper. If the aioli is too thick, whisk in up to 1 teaspoon extra-virgin olive oil or a little cold water to reach desired consistency. Chill until service (can be made up to 24 hours ahead).

Prepare sauce

In a small sauté pan over medium heat, add 1 teaspoon neutral oil and sauté 1 tablespoon finely minced shallot for about 1 minute until softened but not browned. Deglaze with 2 tablespoons dry red wine; reduce by half. Add 1 cup beef demi-glace and bring to a gentle simmer; cook to slightly thicken, about 3–5 minutes.

Mount with butter

Turn heat to low and whisk in 1 tablespoon cold unsalted butter until the sauce is glossy and slightly thickened. Season with 1/4 teaspoon freshly ground black pepper. Keep warm; do not boil after butter is added.

Slice and assemble

Slice the rested Wagyu strip against the grain into 1/2-inch thick slices. Fan slices slightly on a warmed plate alongside a generous portion of tallow fries.

Sauce and garnish

Spoon the warm demi-glace beside or lightly over the steak slices (or serve in a small sauce boat). Add a dollop or small ramekin of lemon-chive aioli to the plate. Finish steak with a light sprinkle of flaky finishing salt (about 1/4 teaspoon) and a crack of black pepper. Garnish fries with optional chopped parsley and serve with lemon wedges.