When I make mashed potatoes, I try to remember to save some of the cooking water to make this bread. If you forget, or don't have any potato cooking water, warm water works fine. The potato water just gives a little finer product.
This recipe came from my husband's mother (who had 7 kids). It's a great way to "stretch" burger. My kids just love it when I make this.
I think it's called Texas Burgers (Tex Burgers) cuz she made it on Texas Toast bread. The hamburger juice gives the bread a great flavor