meat mallet 16 (6-inch) bamboo skewers, soaked in warm water for at least 30 minutes
Cut each 1/4-inch thick slice of meat into portions about 2 to 2 1/2 by 4 to 5 inches. Transfer the slices to sheets of plastic wrap, cover with plastic wrap, and, using the smooth side of a meat mallet, pound the sliced top portions until slices are very thin - ideally about 1/8-inch thick, being careful not to tear the meat. You should have approximately 16 (3 by 6 to 7-inch) rectangular portions of meat.
In a small skillet heat 2 tablespoons of the olive oil on a medium-high heat and saute the onion until tender and translucent. Transfer to a small mixing bowl and add the bread crumbs, cheese, raisins, pine nuts, parsley, and lemon zest. Season with salt and pepper, to taste. Set aside for filling.
Preheat a grill, grill pan, or broiler to high heat.
Lay the beef slices on a clean flat work surface and drizzle with 4 tablespoons of the remaining olive oil, turning to coat evenly. Season with salt and pepper. Divide the bread crumb mixture evenly among the beef slices, about 2 tablespoons each, placing the filling on 1of the short ends. Using your fingers, roll the slices lengthwise up and over the filling until the meat is completely rolled up. Using butcher's twine, tie both ends of each roll firmly to secure. Thread the meat rolls onto 2 skewers, 1 at either end of the roll, and thread bay leaves and onions onto each skewer, then top with a second beef roll and 2 more onions, until you have used all of the ingredients, like a kabob. Lightly brush each skewer with some of the remaining olive oil. You should have 8 double-skewered kabobs, each with 2 beef rolls, 4 onions, and 2 bay leaves.
Grill the skewers, turning occasionally, until meat is charred on the outside but still medium-pink on the inside, about 4 to 5 minutes per side. Set skewers aside to rest for 5 to 10 minutes before serving.