This meal in a bowl is hearty and satisfying, yet the flavors are light and clean. We use beef shanks, as the bones lend the broth both meaty flavor and rich body. They also yield enough meat to give the soup substance. Thick dried Asian wheat noodles such as udon or lo mein are ideal in this soup, but even Italian linguine will work. If you can't find anise seed, the broth is still delicious without it. You can prepare the broth and meat up to three days ahead; refrigerate both until needed, then discard the solid fat from the surface of the broth and proceed. For some spiciness, offer chili-garlic sauce on the side.