Stir together the olive oil, olives, capers, garlic, and anchovy in a small bowl. Set aside.
Place the steak in a large baking dish. Stir together the orange zest, orange juice, shallots, garlic, oregano, paprika, olive oil, red pepper flakes, and salt in a small bowl. Rub the mixture over both sides of the steak to cover completely. Let marinate at room temperature for 1 hour.
Place a grill pan over medium-high heat. Grill the steak for 6 to 8 minutes per side, until a golden brown crust forms and the meat is cooked through. Transfer the steak to a cutting board and let rest for 10 minutes. Slice the steaks against the grain and transfer to a platter. Spoon the olive tapenade over the top and serve.