I roll my own. However, if you've not made pot roast much, I'd suggest checking Paula Deen's recipe, then make your own party. It's not too far from what I do, which comes out great.
Like everyone's saying, low and slow gets it done the right way.
Here's one I made with no vegetables, just onions. I was planning different sides than usual.
And this is the result I usually shoot for. This roast had carrots, onions, mushrooms, celery cooked in the Corningware with it.