Bok choy (Chinese cabbage) is one of the main ingredients of my kids' favorite dish, "Sinigang," a Filipino soup/stew characterized by its sour flavor most often associated with tamarind. It's making my mouth watery as I write this.
Anyway, what do you do with this part of the veggie? Can't really eat it but don't toss it just yet.
I'll give you a hint. What image do you see?
If you see a rose, you're right!
You can use it as a stamp.
I've used acrylic and fabric paints.
You can stamp on t-shirts/sweatshirts/paper, etc.
Here, I stamped on some t-shirt material which I plan to make into a either a scarf or a pillow case (later when time allows.) Stamp away but don't over stamp. Just remember that white space is an element of design.
It doesn't have to be bok choy. It could be anything. Celery, star apple, okra, leaves, rocks, twigs, etc. Design is everywhere. This world is filled with beauty for our pleasure by our Creator.