Beech Bowl & poor mans centre saver 

Green Beech Blank 16/08/2007 cut mounting dovetail rough dress outer diameter reload on recess, face front, & use stiff diamond shaped parting tool to remove part of core, keep plenty of clearance and remove shavings regularly.
when you have got as deep as you feel comfortable with, selecting a point corresponding to the end grain insert Oak or similar wedge/s to split out centre portion.
You are the only one that can assess the strength of the wood to withstand the break-out loads and whether the core base is small enough diameter to break. proceed to rough hollow out bowl Forgot to mention or show drilling screw chuck hole or dovetail recess for remounting before removing core.
hollow out cores for drying, obviously both cores could have been done in sequence from main bowl.
Parcel up for drying 16/08/2007 Finished Salad Bowl 30/08/2007 and the  cores 02/09/2007

Page Revision date: January 10, 2008, 21.18 Hrs.