I seem to always end up burning the onions. I've done this recipe and one other similar one three times to date and I always end up with burnt bits at the bottom of the pan. I have used two different pans (an old copper-bottom pan and a glazed cast iron pan). The burning seems to happen on the introduction of the onions to the pan, which I would think was because the pan was way too hot at the time, but the recipe called for high heat. Should I a) try yet another pan or b) drop the heat some or c) both?

Sounds like your pan is just too hot when it comes time to adding the onions.

Much of cooking (and not burning things) comes down to adjusting the heat throughout the cooking process. Temperatures stated in recipes are generally just estimates as the heat source, the pan, the size of ingredient and even the temperature of the ingredient, i.e., a cold steak vs. a tempered steak, all make a difference. Trust your instincts and pay attention to what is happening in the pan. If it looks like things are too hot or if nothing is happening then don't be afraid to adjust the heat. Hope this helps!

I have made these many times before and I need to freeze them as I use fresh onions from my garden when they are at there peak so freezing is the way to go. I do freeze in small containers mostly because I love them and there are only 2 of us.
Fern Vitense

I only have non-stick pan at home. After reading Rosie G's comment, I went out and bought a stainless steel pan. (Thanks, Rosie!) It took me 1 hour and 15 minutes to make caramelized onion, and it was so worth the time. My husband said he never knew it takes that long to make caramelized onion. Now he will have more appreciation when he eats it. We had it tonight for dinner with filet mignon. The onion was sweet, and tasted delish with the steak. I am planning to use the leftover for pizza and sandwiches.