Cambell's is a little salty I think. But there's no need for homemade. I use Kitchen Basics brand. If you look at Tom Velente's recipe he doesn't require demiglace. I think that's a case of Chef Show-off, because he knows we don't have the instant demiglace that he uses in his restaurant. Yes it comes in powder form. I wouldn't sweat that particular detail. Like I said just use beef stock this time then strain and save the leftover braising liquid for next time.
Hell ya, use the Corning Ware. I just measured my stainless steel half pan and the lip is about 10 1/2 x 12 3/4 it's 4 inches deep. Ya oughta get you one, they're pretty cheap and way better than those disposable things.
Like tortillas, braising aint rocket science.

I was gonna cook mine today but ran into some emergency gardening that had to be done and never got a chance to get it started. Now I got no suppers...;^;

Good coffee, good weed, and time on my hands...