I have a whole celery in the fridge, starting to wilt.

I thought I'd ask here for ideas how to use it up -

I also have a cauliflower that needs using and am making a cauliflower
soup out of that today - I think adding celery to that would detract
rather than augment.

Could make stock... I need to make more chicken/duck stock but don't
have the time for that today. I suppose I could just freeze the whole
thing and use it in stock later?