I purchased a Wear Ever anodized non-stick cake pan... standard round cake pan 9 inches across.
It almost suspends inside a 4qt Anchor Hocking mixing bowl, so I placed the 2 cup Anchor Hocking bowl in the bottom of the larger bowl to act as a support.
Add a glass lid for a skillet, and this works very well.
I cooked a small tv dinner in this today. It took only 2 hours-from freezer to hot enough to eat- in my twin bowl cooker.