It is pretty clear that you turned the chopper on two centers, one for the rim and one for the bottom of the bowl. It appears that the "well" is at a lower level than the bottom (chopping surface). How do you prefer to hollow the well?
I am asking because I am trying to figure out how to make matching cutting boards for some ulu knife kits I'm working on. For chopping nuts, I think I need to make the walls higher than on yours, to stop flying shrapnel. I would also like to shape the bottom and sides so that the ulu knife can scrape them clean, and into a bowl.
For mine, I have a few more design criteria that I'm working on, but discussing any more of them at this point would only confuse the current discussion.