Bill Tindall, E.Tn.
BTW I chop nuts on our board that is essentially identical. One chops with a rolling motion of a chefs knife and little kinetic energy is imparted to the particles.
Anybody with a lathe would turn the shallow bowl part then proceed as I have.
After gluing up the blank I drill a line of holes around the edge to get clearance for what comes next.
I then free hand route the inside of the "bowl" with a bit with a rounded end that I don't remember what it is called
Then I free hand route out the bottom of the bowl. Band saw the circle. Smooth circle and route a 1/4 round on bottom.
Now the neat part. Mount in a router sled with one end propped up 3/4". Lock in place using the cut-offs from making the circle screwed to base of sled. Route away the lip going from zero to the bottom of the bowl on the opposite side. Sand smooth.
Flip and add a cleat to bottom to raise the rimless end up level with the opposite side (I think I have a picture of this cleat in my Gallery)