Can I roast in glass?
Dude you said you have cast iron. Cast iron rules. And it performs very well in the oven. No contest against glass and you can make pan sauce on the stove-top after the roasting is finished. My favorite pan to make roast chicken with is my 12" Lodge cast iron skillet. Glass is probably better at roasting than cheap cookie style sheets, because it keeps the heat distribution fairly smooth. But glass will not hold up well to heavy roasting use and will eventually ruin your dinner when it cracks or shatters. All Clad makes a great roasting pan with wire rack. But for most roasting a simple cast iron skillet works well and is indestructible.