Meat is precious and Buddhist traditions are strong in Vietnam, which is why dishes of beef are considered a luxury. Clever cooks cut tender, marbled cuts into small pieces so they soak up flavor, then cook them quickly and serve them hot with aromatic herbs. Here, the peppery, salty-sweet, juicy beef mingles with the light salad dressing to create a great sauce that pools on the platter, perfect for drizzling over rice. Watercress leaves warm and wilt under the Shaking Beef (so named for the back-and-forth shaking of the pan), while their stems remain crunchy. In the summer, sub cherry tomatoes for the radicchio. For a stunning appetizer, serve the sautéed beef with some fresh herbs and toothpicks for easy sharing.