How to Make It
Light a grill. Rub the steaks all over with 3 tablespoons of the spice rub and let stand for 5 minutes.
Meanwhile, in a medium bowl, combine the yogurt, scallions, garlic, jalapeños and the remaining 1 1/2 teaspoons of the spice rub. Stir in the olive oil and season with salt and pepper.
Brush the steaks lightly with olive oil and grill over high heat, turning occasionally, for 7 to 8 minutes for medium-rare meat. Brush the pitas with olive oil and grill until lightly toasted, about 30 seconds. Transfer the steaks to a cutting board and let rest for 5 minutes. Thinly slice the steaks across the grain. Transfer the steaks to a platter and serve with the toasted pita, yogurt sauce and lettuce leaves.