"The essentials of the dish include thinly sliced beef, red onion, scallions, watercress, and a soy-based sauce. “Shaking” refers to how you move the skillet in order to cook the meat, which at The Slanted Door is cubes of filet mignon. The vegetables play a supporting role, and the flavorful sauce at the end is mounted with butter, which thickens it. It evokes the taste of the rich, red wine reductions that pool around steakhouse filets." Try it out here, at Food52!