Instead of a combo cooker...

Toast

I've been baking bread for many years now--sourdough with my own milled flour for several of those--and have recently bought Tartine and am gleefully exploring this beautiful book. Here's my question: rather than purchase a combo cooker, especially since I like to bake batards as well as boules, I wonder if y'all think the following could work. After breaking several baking stones and deciding against purchasing a really heavy, thick stone, I have for many years used a Lodge cast iron pizza pan for my bread. It has worked perfectly. Now I wonder if I could simply invert a 9 qt. cast iron Dutch oven over that pan to create something akin to the combo cooker or a cloche. My concern is that these ovens do have a small spout, which means they might not make a perfect seal.

Ideas?

Why don't y'all just try it and see? Be sure to let us know.

There is a commercial version that works with batards  https://www.fourneauoven.com  but it is quite expensive.  I thought of making a similar version out of steel but have not gotten around to it.  I have a combo, and it has a ridge that may be a more effective seal to keep in moisture, than just using a inverted lid, but i haven't done any direct testing to see if the combo gets better results,  so please do let us know how it works out.