2poundsskirt steak,can be replaced with flank or flap steak
1/4cuproughly chopped fresh parsley
Preheat a grill or grill pan to high.
Pulse the kalamata olives, shallot, garlic, rosemary, red pepper flakes, 2 tablespoons olive oil and the juice of 1/2 lemon in a food processor; season with salt and pepper.
Season steak with salt and pepper and rub 1 heaping tablespoon olive mixture all over the steak, set aside 15-20 minutes.
Toss the remaining olive mixture with the castelvetranos, tomatoes, parsley, the remaining 2 tablespoons olive oil and the juice of the remaining 1/2 lemon in a small bowl.
Grill the steak until browned on one side, about 5 minutes. Flip and cook about 5 more minutes for medium rare. Transfer the steak to a cutting board and let rest 5 minutes. Cut in half; reserve one half for steak sandwiches . Thinly slice the remaining steak against the grain and top with the olive-tomato tapenade.