I don't have dish HD yet, but what is this stretching you describe? Why is a stretched image coming from the satellite? Usually it's a result of having your tv in the wrong mode...
My thanks to Pepper for giving us that succinct explanation of stretch o vision. And I did not mean to imply Food Network is one of the worst. In fact, they are one of the better ones, IMHO.
Sometimes, the content provider decides to upconvert, stretch, spindle, fold and mutilate an SD or ED source program into something they think they can pass off as HD. And sometimes the stretch is not done evenly across the screen. Sometimes the middle is more or less normal, and the edges are stretched more, and maybe at varying rates.
As more material is originally captured in HD, we should see less and less of this. But don't expect everything on an "HD" channel to really be "HD" today.