French Dip Sandwich

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  Beef Flank Steak, Boneless(680g)
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  Kosher salt
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  Freshly cracked black pepper
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  Bread, French Or Hoagie Roll
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  Butter(90g)
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  Garlic powder(10g)
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  Cheese, Gruyere(480g)
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  Parsley, Fresh
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  Low Sodium Beef Broth(960g)
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  ¼ teaspoon dried thyme
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  1 teaspoon kosher salt
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  1 teaspoon sherry wine
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  Worcestershire Sauce(15g)

  Lea & Perrins is the standard. A little goes a long way.

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  Garlic powder(10g)
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  Onion powder(10g)

Instructions

1. 1Pat the flank steak dry and season generously with salt and pepper on both sides. Heat a large cast-iron skillet over high heat until smoking, then sear the steak 3 minutes per side until the internal temperature reaches 135°F on an instant-read thermometer for medium-rare. Transfer to a cutting board and let rest 5 minutes, then slice as thin as possible against the grain and set aside.
2. 2In a medium saucepan over medium heat, combine the beef broth, Worcestershire sauce, garlic powder, and onion powder. Whisk until fully combined and simmer for 5 minutes, stirring occasionally, until the flavors meld.
3. 3Butter the inside of each French roll and sprinkle evenly with the garlic powder. Arrange the rolls open-faced on a rimmed baking sheet.
4. 4Preheat the oven broiler to high. Working quickly, dip the steak strips into the au jus and distribute evenly across one side of each roll—about 2 ounces per sandwich. Top each sandwich with the Gruyere cheese, dividing it evenly.
5. 5Place the baking sheet under the broiler 4–6 inches from the heat source and broil for 2–3 minutes, watching constantly, until the cheese is melted and beginning to brown.
6. 6Remove the baking sheet from the oven and garnish each sandwich with fresh parsley if desired.
7. 7Divide the remaining au jus evenly into 4 small ramekins or dipping bowls—about ¾ cup per serving.
8. 8Serve each sandwich immediately alongside its corresponding ramekin of au jus for dipping.