Steak Frites Recipe

Prepare and soak

Wash and peel the potatoes if you prefer (skin on is fine). Cut each potato into 1/3–1/2 inch (8–12 mm) sticks for classic frites. Place cut potatoes in a large bowl and cover with cold water (about 4 cups). Stir and let soak at least 30 minutes, up to 2 hours, to remove excess starch. Drain and rinse when ready, then pat completely dry with clean kitchen towels or paper towels.

First fry (blanch)

Heat 1–1.5 inches of neutral oil in a heavy pot or dutch oven to 300°F (150°C). Working in batches, fry the dried potato sticks for 4–6 minutes until pale and just tender but not browned. Remove with a slotted spoon to a tray lined with paper towels and let drain. Keep oil at 300°F between batches.

Second fry (crisp)

Increase oil temperature to 375–390°F (190–200°C). Fry the blanched fries in batches for 2–3 minutes until golden brown and crisp. Remove to a rack or paper towels, immediately season with fine sea salt (about 1 tsp divided) and freshly ground black pepper (about 1/2 tsp). Keep warm in a single layer in a low oven (200°F / 95°C) while you cook the steak and finish the sauce.

Crush peppercorns

Coarsely crush the black peppercorns using a mortar and pestle or by placing in a zip-top bag and crushing with a heavy pan. You want large grains of pepper, not fine powder.

Sauté shallot and flambé

In a small skillet over medium heat, melt 1 tablespoon unsalted butter. Add the minced shallot and sauté gently until translucent, about 1–2 minutes. Increase heat to medium-high, add the brandy or cognac, tilt the pan away from you and ignite carefully with a long match or let it reduce by half if you prefer not to flambé. Allow alcohol aroma to evaporate and reduce for about 1–2 minutes.

Finish butter

Remove the pan from heat and swirl in the remaining cold butter (3 tbs), a little at a time, until incorporated and the sauce is glossy and emulsified. Stir in the crushed peppercorns, Dijon mustard, lemon juice and sea salt. Taste and adjust salt or pepper. Keep warm (very low heat or off-heat in a warm spot) until serving; the beurre au poivre should be spreadable but cool enough to hold shape on the steak.

Bring to room temperature and season

Remove the flat iron steak from the refrigerator 30–45 minutes before cooking to come to room temperature. Pat dry with paper towels. Season both sides generously with kosher salt (about 1 tbs total) and freshly ground black pepper (about 1 tsp).

Sear the steak

Heat a heavy cast-iron skillet over high heat until very hot. Add 2 tbs neutral oil and swirl to coat. When oil is shimmering and just smoking, add the steak. Sear without moving for 3–4 minutes until a deep brown crust forms. Flip and add 1 tbs unsalted butter; as butter melts, tilt the pan and spoon the melted butter over the steak for 1–2 minutes while continuing to sear the other side. For medium-rare, cook until an instant-read thermometer reads 125–130°F (52–54°C), about 3–5 minutes more depending on thickness.

Rest

Transfer the steak to a cutting board and loosely tent with foil. Let rest 8–10 minutes to allow juices to redistribute. This will also let the carryover cooking bring the steak to about 130–135°F (54–57°C) for medium-rare to medium.

Slice and finish

Slice the steak against the grain into 1/4–1/2 inch thick slices. Place slices on a warmed serving platter or individual plates. Top each portion with a generous dollop (about 1–2 tbs) of beurre au poivre; the butter will melt onto the warm steak creating a peppery, glossy finish. Sprinkle with chopped parsley if using and serve immediately with the crispy frites and lemon wedges on the side.

Arrange fries alongside the sliced steak, finish fries with an extra pinch of salt if needed, and offer lemon wedges for those who like a bright squeeze. Serve immediately while steak is warm and butter is glossy.