Ive had the veggie burger and the veggie chilli at the Spice Mill (as part of the all day dining) and both were yummy. Other places on the all day dining have veggie options but I didn't try them as I am not actually veggie and they just looked great. I know there is also a veggie pizza and a veggie wrap and you can also have a kids meal if you wish. There is a picture of the chilli bowl in a thread I did a few posts down.
The all day dining is $29.99 per adult and you get a main meal, drink and dessert/side each time through the queue. You can go through the queue as many times as you like (for whole or part meals or even just a drink). It is really good and I would do it again and could happily do it by only eating veggie choices even though I eat meat.
Hope that helps.