Shio Koji–Marinated Flank Steak

Steps

1. 1

   Cut the well-trimmed flank steak in half lengthwise, then halve each piece crosswise to create 4 smaller steaks.

2. 2

   Place the steaks and 3 tablespoons of shio koji in a bowl and rub the shio koji evenly into all sides of the meat.

3. 3

   Cover the steaks and refrigerate for at least 4 hours or up to 24 hours to marinate.

   Start 4-hour timer
4. 4

   Adjust an oven rack to the middle position and preheat the oven to 275°F (140 °C) (135°C (275 °F)).

5. 5

   While the oven heats, set a wire rack inside a rimmed baking sheet.

6. 6

   Using a damp towel, wipe the shio koji from the steaks; it is fine if a few grains remain on the surface.

7. 7

   Sprinkle the steaks with 1/2 teaspoon of pepper.

8. 8

   Set the steaks on the prepared wire rack and transfer the baking sheet to the oven.

9. 9

   Cook until the thickest part of the largest steak registers between 130°F (54 °C) and 135°F (57 °C) (54°C (129 °F) to 57°C (135 °F)), approximately 25 to 30 minutes.

   Start 30-minute timer
10. 10

    Heat 1 teaspoon of vegetable oil in a 12-inch nonstick skillet over medium-high heat until the oil is shimmering.

11. 11

    Add the steaks to the skillet and cook, pressing them gently into the pan, until they are browned and slightly charred in spots on both sides, about 1 to 2 minutes per side.

    Start 2-minute timer
12. 12

    Transfer the steaks to a cutting board and cut on the bias against the grain into 1/2-inch-thick slices.

13. 13

    Serve immediately, passing flake sea salt and lemon wedges separately if desired.