Pat the coulotte steak dry with paper towels. In a shallow dish or zip-top bag combine 2 tbsp olive oil, 1 tbsp soy sauce, 1 tsp Worcestershire, minced garlic, 1 tsp black pepper, 1 tsp kosher salt and optional thyme. Add the steak and turn to coat. Marinate at room temperature for 30 minutes or refrigerate up to 4 hours. If refrigerated, bring to room temperature 30 minutes before cooking.

Sear and Rest

Heat a heavy skillet (cast-iron preferred) over medium-high until smoking. Add the steak (wipe excess marinade off to avoid flare-ups). Sear 3–4 minutes without moving until a deep brown crust forms. Flip and sear 3–4 minutes for medium-rare (internal temp about 125–130°F / 52–54°C). Reduce time for rarer doneness or increase for more done. In the last 60 seconds, add 1 tbsp butter to the pan and spoon melted butter over the steak (basting). Transfer steak to a cutting board, tent loosely with foil and rest 8–10 minutes before slicing thinly against the grain.

Truffle Parmesan Fries

Prepare Potatoes

While steak marinates or rests, rinse and scrub the potato. Cut into 1/3-1/2 inch thick matchsticks (fries). Soak cut fries in cold water for 20–30 minutes to remove excess starch; this yields crisper fries. Drain and pat completely dry with clean kitchen towels or paper towels.

Cook Fries

Heat oil in a heavy pot or deep-fryer to 325°F (163°C) for the first blanch. Fry the potatoes in batches for 3–4 minutes until soft but not colored. Remove to a wire rack lined with paper towels. Raise oil temperature to 375°F (190°C). Fry again in batches until golden and crisp, about 2–3 minutes. Drain on paper towels.

Season

While hot, transfer fries to a large bowl. Drizzle with 1 tsp truffle oil, sprinkle 1 tsp garlic powder, 1 tsp kosher salt, 1/2 tsp black pepper and the grated 1 oz Parmesan. Toss gently to coat. Finish with 1 tbsp chopped parsley and adjust seasoning as needed.

Truffle Cream

Make Sauce

In a small saucepan over low heat, warm 1/2 cup heavy cream with 1 tbsp butter, stirring until butter melts. Whisk in 1 tbsp grated Parmesan and 1/2 tsp Dijon mustard. Keep on low heat until sauce slightly thickens (2–3 minutes) — do not boil. Remove from heat, stir in 1/2 tsp truffle oil, and season with 1/4 tsp salt and 1/4 tsp black pepper. Taste and adjust truffle oil or salt as desired. Keep warm until serving.

Plating & Finish

Slice Steak & Plate

Slice the rested coulotte thinly against the grain. Arrange slices on a warmed plate. Spoon a little of the truffle cream alongside or lightly over the steak (reserve some for the fries if desired).

Serve Fries

Pile truffle Parmesan fries next to the steak. Sprinkle fries and steak with a pinch of flaky sea salt and the remaining chopped parsley. Serve immediately so fries stay crisp and sauce remains warm.