In one part haku gives chihiro onigiri, though it looks plain b/c I didn't see any filling!
The part where the parents eat and turn into pigs features some really odd looking food, I think they mention that they don't even know what kind of food it is.
There's also the part where they visit that old, nice witch. She gives them tea and cake... it kinda looks like cheesecake but I dunno
