Chef Charles Phan prefers tender baby bok choy but if you can only find mature heads, separate the leaves from the stems, cut the stems into one-and-a-half-inch pieces, and stir-fry them separately so the leaves don’t overcook.
Chef David Chang flavors this fabulous broth with dried shiitakes; fresh shiitakes add intensity. The highlight: simple noodles thrown in at the end. “They’re based on the udon I learned to make in Tokyo,” Chang says.