Marinated Flank Steak Recipe

Prepare the marinade

In a bowl or shallow dish, whisk together soy sauce, 3 tbsp olive oil, red wine vinegar, brown sugar, minced garlic, thyme, black pepper, kosher salt, and red pepper flakes until sugar dissolves.

Marinate the steak

Place flank steak in a resealable bag or shallow dish and pour marinade over it, turning to coat. Seal and refrigerate for at least 2 hours and up to 8 hours (preferably 4–6 hours). Remove from fridge 30 minutes before cooking to come toward room temperature.

Sear and grill

Preheat a heavy skillet (cast-iron) over high heat or heat a grill to high. Remove steak from marinade and pat dry with paper towels (reserve marinade). Add 1 tsp oil to the hot pan and sear steak 3–4 minutes per side for medium-rare (internal temp 125–130°F / 52–54°C), depending on thickness. For thicker cuts, finish in a 400°F oven for 3–5 minutes if needed.

Rest and slice

Transfer steak to a cutting board, tent loosely with foil, and rest 8–10 minutes. Slice thinly across the grain into 1/4" slices.

While the steak rests, make the sauce. In the same skillet used for steak (wipe excess fat leaving browned bits), melt 2 tbsp butter over medium heat. Add finely minced shallots and cook until softened and translucent, about 2–3 minutes.

Stir in 1 tbsp tomato paste and cook 1 minute to remove raw flavor. Pour in 1/2 cup dry red wine, scraping up browned bits with a wooden spoon. Reduce wine by half, about 2–3 minutes over medium-high heat.

Add 1 cup beef stock, bay leaf, and thyme sprig. Bring to a simmer and reduce until slightly thickened, about 6–8 minutes. Remove bay leaf and thyme sprig.

Lower heat and whisk in 1 tbsp cold butter until glossy, then season with 1/2 tsp salt and 1/4 tsp black pepper. If desired, strain sauce through a fine mesh sieve for a smooth demi-glace. Keep warm.

If you reserved marinade: bring it to a boil in a small saucepan for 2 minutes to kill bacteria, then add a few tablespoons to the sauce while reducing for additional flavor (optional).

Frying method (recommended)

Rinse cut potatoes under cold water until water runs clearer to remove starch. Pat thoroughly dry. Heat 2 cups oil in a heavy pot to 325°F (163°C). Blanch potatoes in batches for 3–4 minutes until soft but not colored. Remove and drain on paper towels. Increase oil to 375°F (190°C) and fry in batches until golden and crisp, 2–3 minutes. Drain, season with 1 tsp salt and 1/4 tsp pepper, and keep warm.

Oven method (alternative)

Preheat oven to 425°F (220°C). Toss dried potato sticks with 1–2 tbsp oil and spread in a single layer on a baking sheet. Bake 20–30 minutes, flipping halfway, until golden and crisp. Season with salt and pepper.

In a large bowl, whisk together lemon juice, 2 tbsp extra-virgin olive oil, 1/4 tsp salt, and 1/4 tsp black pepper to make a quick vinaigrette.

Add 4 cups baby arugula and 1 cup halved cherry tomatoes to the bowl and toss gently to coat. Top with 1/4 cup shaved parmesan. Keep chilled until plating.

Arrange a bed of arugula salad on each plate. Fan sliced flank steak over the salad or place alongside.

Spoon 2–3 tablespoons of shallot demi over the steak and around the plate. Add fries to the side.

Garnish with chopped parsley if using and serve immediately so steak is warm and fries are crisp.