I've been trying to come up with ways to have udon soups using ingredients readily available in the West and this one is it. Udon is Japanese wheat based thick noodle. You can use either dry udon (cooked per package instruction - make sure you rinse it very well in cold water) or fresh udon. If using chicken stock, best to use homemade, but best not to use chicken stock that has too much chicken taste such as Trader Joes. Swanson is ok. If using store bought broths, best to dilute it with 50% water so it's not so strong tasting.