Steakhouse-Style Grilled Marinated Flank Steak

Ingredients

• 1/2 cup Worcestershire sauce
• 1/4 cup soy sauce
• 3 tablespoons brown sugar
• 4 anchovy filets
• 2 cloves garlic
• 2 tablespoons Dijon mustard
• 2 tablespoons tomato paste
• 1/2 cup vegetable oil
• 2 tablespoons chopped chives
• 1 medium shallot, minced
• 1 whole flank steak, about 2 pounds

Directions

1. In a blender, add the Worcestershire sauce, soy sauce, brown sugar, anchovies, garlic, mustard, tomato paste, and vegetable oil. Blend until the mixture turns smooth, creamy, and fully emulsified. Pour 1/3 of the marinade into a small container, mix in the chives and shallots, and set it aside. Put the flank steak in a gallon-sized zipper-lock bag with the rest of the marinade. Squeeze out the air, close the bag, and marinate the meat for at least 1 hour and up to 12, turning it now and then.
2. Take the steak out of the marinade and blot it dry with paper towels. Light a large chimney packed with coals, then let them burn until they are coated with grey ash. Arrange the coals across 1/2 of the grill grate, leaving the remaining side without coals. Set the cooking grate on the grill, cover it, and heat it for 5 minutes. Clean the grates well, then lay the flank steak on the hot side. Cook until the first side is deeply charred, about 3 minutes. Turn the steak over and char the other side, about 3 minutes longer. Move the steak to the cooler side, cover the grill, and continue cooking until an instant-read thermometer inserted into the center reads 125 degrees F for medium-rare, or 135 degrees for medium. Place the steak on a cutting board, cover it loosely with foil, and let it rest for at least 5 minutes. Slice and serve with the reserved marinade at the table.
3. For an indoor finish, warm 2 tablespoons vegetable or canola oil over high heat in a large stainless steel or cast iron skillet until it shimmers. Take the steak out of the marinade and dry it thoroughly with paper towels. Set the steak in the skillet and cook, turning it often, until an instant-read thermometer reads 125 degrees F for medium-rare, or 135 degrees for medium. If the steak starts smoking heavily or threatening to burn, lower the heat as needed. Move the steak to a wire rack set inside a rimmed baking sheet and rest it for 5 to 10 minutes. Slice and serve with the reserved marinade at the table.