1 1/4 - 1 1/2 pound skirt steak
kosher salt, to taste
freshly cracked black pepper, to taste
1/2 cup mayonnaise
1/4 cup finely minced fresh herbs, such as tarragon, parsley, chives, dill, or cilantro
4 4-inch square focaccia or ciabatta rolls, halved
2 ounces arugula
- Preheat the oven to 500°F. Place cast iron skillet in the oven and let it heat for 20 minutes.
- Meanwhile, place skirt steak on a cutting board and season generously on both sides with kosher salt and pepper to taste. Halve the steak or cut into thirds to ensure it will fit in the skillet. Stir together the mayonnaise and herbs. Arrange the halved squares of focaccia on a work surface. Spread each half with a thin layer of the herbed mayonnaise.
- Carefully remove skillet from the oven and place over high heat. Lower steak into pan and cook undisturbed for 2 to 3 minutes or until nicely browned with edges beginning to cook. Flip, and cook for 2 minutes more. Transfer to a cutting board and let rest for 10 minutes before slicing against the grain into thin strips.
- To assemble: Pile 4 to 5 slices steak onto each bottom half of bread. Top with a handful of arugula. Close sandwich and serve immediately.