Flank Steak and Marinade:
- 1/4 cup white balsamic vinegar
- 1/4 cup grapeseed oil
- 2 tablespoons Worcestershire sauce
- 2 teaspoons minced fresh thyme leaves
- 2 teaspoons minced fresh parsley leaves
- 1 tablespoon minced garlic
- 1 lemon, juiced
- 1 1/4 teaspoons salt
- 3/4 teaspoon freshly ground black pepper
- 1 to 3 pounds lean flank steak, fat removed
- 1/4 pound double-cream Brie, cold
- 2 tablespoons cornstarch
- 1 cup dry red wine
- 1 tablespoon minced fresh thyme leaves
- 1 teaspoon minced garlic
- 1 teaspoon ground nutmeg
- Salt and freshly ground black pepper
In a small bowl, whisk together the vinegar, oil, Worcestershire, thyme, parsley, garlic, lemon juice, and salt and pepper. Put the flank steak in a wide shallow dish and coat with the marinade. Refrigerate for 45 minutes to 1 hour.
Preheat a grill on high.
Remove the outer skin (rind) of the brie and dice it into 1/2-inch cubes. Add them to a small bowl and toss them with the cornstarch. In a medium saucepan over high heat, add the wine and bring to a boil. Add the brie and stir until the cheese has melted. Once melted, reduce the heat to medium-low and stir in the thyme, garlic, nutmeg, salt and pepper, to taste. Cook for 5 to 6 minutes. Remove the fondue from the heat and transfer it to a fondue pot to keep warm.
Remove the steak from the marinade, straining the excess marinade and put it in the middle of the preheated grill. Cook until desired temperature is reached, about 9 to 10 minutes per side. Remove from the grill to a cutting board and let rest for 5 to 10 minutes.