How to Make It
Place steaks on a work surface. Using a Jaccard meat tenderizer or fork, poke steaks all over until well tenderized (or ask your butcher to tenderize the steaks). Sprinkle with salt, pepper, and oregano. Let stand at room temperature 1 hour.
Meanwhile, open bottom and top vents of a charcoal grill completely. Light charcoal chimney starter filled with briquettes. When briquettes are covered with gray ash, pour in an even layer on bottom of grill. Place lamb steaks on oiled grate; grill, uncovered, turning occasionally, to desired degree of doneness, about 10 minutes for medium. Transfer to a platter; let rest 10 minutes.
To serve, spoon 2 tablespoons Garlic-Caper Vinaigrette over each steak. Top evenly with Marsala Cipollini Onions, syrup from onions, and Pistachio Gremolata. Serve immediately with steak knives.