On Sat, 03 May 2008 00:21:51 -0700, Leonard Blaisdell
> wrote:

>I cook a pot roast for about two hours before I add vegetables. Then I
>add medium onions for an hour,

For the start of a roast, I slice onions one half inch thick and put
them under the roast for a rack. But we still add onions sliced in
quarters two hours later. The rack onions dissolve and the quarter
slice will hold its shape.