Heidi, DO read JoanN’s posts in the Les Halles thread Susan linked. It is important to use a shallow roasting pan, because onions exude a tremendous amount of water and you need quick evaporation, lest the onions stew. Your cast iron pot is not ideal. Slice them from pole to pole, to help them retain some shape. Rings will break down too fast. When 5#bags of onion are on sale, I buy extra and caramelize a bagful. They freeze well. I have done both stovetop and oven methods, and tend to prefer stovetop since my nose and ears tell me how they are progressing. Either way, there’s no getting around babysitting them, with frequent stirring, if you want good results. It takes a few hours, from peeling to cooling, but I just plan on doing them when I can stick close to the stove/oven. Also, if you freeze the sliced onions, you can cook them direct from frozen in less time than cooking right after slicing. This is because freezing ruptures cell walls, so the water releases quicker. Often, the onions are the most time-consuming part of cooking. Having frozen sliced onions, and/ or frozen sauteed onions available speeds things along.