Step 1: Draw your design on a computer. CAM the part
I started with an elipse sized appropriately for the center element, and then added several more concentric ellipses around it. I drew a couple of vertical lines just off the center line, about 1/4" apart, then used the trim function to get a bunch of semi-ellipses. The picture shows the process almost done.
Save the file in DXF format.
Since I planned to use the Flow Waterjet to do the cutting, I rendered the cutting paths in their Flowpath software. Since it was a simple design, their AutoPath feature created an acceptable cutting path. I noticed it was not maximally efficient, but it wasn't worth the effort to create all of the paths manually.
I saved the file and then headed over to the water jet to make my cuts.