4 beef tournedo fillets (6-8 ounces each, about 1 inch thick), at room temperature
Coarse salt and pepper
Extra virgin olive oil (EVOO) or vegetable oil, for drizzling
6 tablespoons butter, softened
1 shallot, minced
2 cloves garlic, minced
2 tablespoons tomato paste
2 tablespoons fresh parsley, chopped
2 teaspoons Worcestershire sauce
1/2 teaspoon dried oregano
4 slices fresh mozzarella
4 brioche buns, lightly toasted
A splash of vermouth, white wine or sherry
Pre-heat a large, heavy skillet, preferably cast iron, over medium-high heat. Season the meat with salt and pepper. Drizzle a little oil into the hot pan. Add the beef and cook, turning once, until nicely browned, about 6 minutes.
Meanwhile, in a small bowl, using a fork, mash the butter, shallot, garlic, tomato paste, parsley, Worcestershire sauce and oregano.
Top the beef with the cheese, cover the pan and cook over medium heat until the cheese is melted, about 3 minutes. Invert the beef, cheese side down, onto the bun bottoms. Reserve the skillet.
Stir the vermouth into the reserved skillet over medium-high heat and scrape up any browned bits. Spoon the pan sauce onto the beef and top each piece with one-quarter of the butter-tomato mixture so that it melts down over the meat and is soaked into the bun bottoms. Cover with the bun tops.