Oh, you can put them in mushroom stew, or pumpkin soup, chestnut veloute, rice with vegetables, all sorts of stuff. Chestnuts have a somewhat sweet, caramel-y flavour that still feels kind of earthy in a sense. So you can put them in many kinds of soups and stews if you feel like the flavour fits. Generally I wouldn't try putting chestnuts in something with a very eatery consistency, or legume based stuff. The only legume I can think of that maybe could go together with chestnuts is maybe chickpeas? Or giant baked beans? Perhaps, I haven't tried any of that stuff. I'd say get a few chestnuts and try them out to see what their flavour is like and then decide what you could put them in. They'd probably be nice in ramen too.

Also don't try to eat them without boiling them or roasting them at all. It's not bad for you or whatever, it just doesn't taste good. Also barbecuing them or putting them in a fireplace or whatever is fun because they often blow up.