I just bought this knife from Sears that has a little cutting board attached. I gave it a test drive and it works great for cutting pepperoni. It should be good for cutting onions, carrots, mushrooms etc. The knife separates from the cutting board (which is plastic) and can be used by itself. The blade is razor sharp and made in Germany of stainless steel.
The name of the device is "Slice-Pro" and can be found at this URL. The price is listed at $19.95 but Sears has them on sale for $14.95.http://www.sears.com/sr/javasr/product.do?BV_UseBVCookie=Yes&vertical=APPL&pid=00809700000&tab=del#tablink