From my go-to-vegan-cookbook Veganomicon:
Kabocha-Udon Winter Stew
Light and yet hearty with a clean Asian taste.
It was the first time I have heard and used Kabocha squash, yes, a Japanese pumpkin not the drink (that would be Kombucha). I was lucky to find it in Oldenburg's main Asian store. It has very sweet orange flesh and you can cook it with its green peel, which will soften. But you can also use butternut or any other sort of squash. And I just love Udon noodles for big slurping fun (I have once heard that slurping your hot soup is a "must" in Japan to bring out the flavours, and not bad table manners).
For the broth you also need Kombu kelp, which I had ordered online last summer (since then I had wanted to make the soup, but really wanted to wait for a winter day, a bit weird maybe, and then I saw that the Kombu was about to expire soon and headed for the kitchen). The Kombu cooks up a nice broth with the ginger and soy sauce.
One thing from the recipe I didn't put in the stew: 1/3 cup of sake. I don't drink alcohol and who knows how the children would have reacted to it...