Step 1

Pull the flank steak out of the refrigerator 30 minutes before cooking. Preheat a grill or grill pan to medium high heat. Halve the rolls horizontally. Drizzle the rolls evenly with the olive oil and grill for 2 to 3 minutes or until lightly toasted. Set aside.

Step 2

Season the steak evenly on both sides with 1 teaspoon of the kosher salt. Season the onion slices with 1 teaspoon olive oil and the remaining 1/2 teaspoon salt being careful to keep them intact so they are easier to grill. Place the meat and the onions on the grill and grill and cook for 4 to 5 minutes per side, or until an instant read thermometer reads 135 degrees F. Remove the onions for the grill when they are deep golden brown on both sides. Allow the meat to rest for 10 minutes before slicing.

Step 3

Meanwhile, in a large bowl combine the remaining 2 tablespoons olive oil, chopped anchovies, oregano, balsamic, giardiniera, olives and basil. Mix well to combine. Thinly slice the rested steak against the grain. Add the sliced steak, grilled onions and any accumulated juices from the plate to the bowl with everything else. Toss well to combine.

Step 4

Place two slices of provolone on each toasted roll. Fill each roll with 1 cup of arugula. Divided the steak filling with all of the mixture evenly among the 3 rolls. Cut them in half and serve.