Tender, inexpensive sirloin flap steak—another name for the “tails” of porterhouses and T-bones—is ideal for
kebabs. It’s well marbled (the fat adds flavor on the grill), and its long, narrow shape makes it easy to cut into cubes. Robust and beefy on its own, flap steak tastes even better after being marinated in a paste of olive oil, cumin, coriander, and fresh oregano.