Celery leaves are edible and more nutritious than the stems.Try making tsukudani with them.
I grow celery. Celery leaves have perfect nutrients.I make Tsukudani, instead of throwing them away.
Check the nutrients of celery leaves in my blog. "Farmer's Kitchen"http://ameblo.jp/farmers-keiko/entry-10667501518.html
Enjoy Japanese food around the world.