Jul 14 2026
RestaurantsThe OspreyPrime Flank Steak Recipe

Prime Flank Steak Recipe

Inspired by The Osprey
Time1h
Serves4

Beef fat béarnaise, fries

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Ingredients

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Flank Steak

Béarnaise Sauce

Method

Flank Steak

  1. 1

    Prepare the Steak

    Take the flank steak out of the refrigerator and let it come to room temperature for about 30 minutes before cooking.

  2. 2

    Season the Steak

    In a small bowl, mix together olive oil, salt, black pepper, garlic powder, and chopped fresh rosemary. Rub the mixture evenly over the steak.

  3. 3

    Grill the Steak

    Preheat a grill or grill pan over medium-high heat. Cook the steak for about 5-7 minutes on each side for medium-rare, or until it reaches your desired doneness. Remove from the grill and let it rest for 10 minutes before slicing.

Béarnaise Sauce

  1. 4

    Melt the Butter

    In a small saucepan, melt the unsalted butter over low heat and set aside.

  2. 5

    Prepare the Reduction

    In another saucepan, combine shallots, white wine vinegar, and tarragon. Cook over medium heat until reduced by half. Strain the mixture into a bowl and let cool.

  3. 6

    Make the Sauce

    In a heatproof bowl, whisk together the egg yolks and water. Place the bowl over a pot of simmering water (double boiler). Whisk continuously until the mixture thickens. Gradually whisk in the melted butter until smooth. Stir in the shallot reduction, salt, and black pepper to taste.

Fries

  1. 7

    Prepare the Potatoes

    Peel the russet potatoes and cut them into thin strips to make fries.

  2. 8

    Heat the Oil

    In a deep pot or fryer, heat the vegetable oil to 350°F (175°C).

  3. 9

    Fry the Potatoes

    Carefully add the potato strips to the hot oil in batches. Fry until golden brown and crispy, about 4-5 minutes. Remove with a slotted spoon and drain on paper towels. Season with salt to taste.

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