solar cooking pot roast. 325 degrees most the time. with this set up, you can achieve 400 degrees easily. be sure to use oven worthy glass bowls. don't put the oven directly in the focus point, like in my hot dog video, or your glass will shatter. keep it in front of or behind the focus point to maintain your temp. the closer your oven is to the focus point (in front of or behind) the hotter your temp. you also should remove the lid while it is still very hot to prevent bowls from shattering, due to glass contracting as they cool. i found that by cooking in front of the focus point, i don't have to move my oven or the lens as much as the sun tracks across the sky.