A properly seasoned cast iron pan can be non-stick but the temperature has to be right, you need shortening, and you can't just put any amount of food in it at any temperature.
Stainless is can do the job too, but temperature and shortening is even more important. There's a much tighter window of temperature that it works at. You do the "water drop test" to determine that it's ready. See youtube for an infinity of videos on how to check the stainless is at right temperature!
I've given up on non-stick pans. They're semi-disposable because the don't last very long and you don't want to use them at high temperatures. All it takes is a little bit of skill to never have to use non-stick teflon pans.
I use cast iron for everything I possibly can, but there is one use case I still need non-stick pans for: frying eggs. The only way to get them to not stick in even the best seasoned cast iron pan is copious amounts of oil, which seems like it's probably worse than a few molecules of PTFE derivates.
I've been frying eggs in my cast iron every morning for years, works like a charm! I use a small slice of butter and it's nonstick. The eggs don't freely slide around like they would in a non-stick pan, but after frying on one side for a moment I can easily move them with a metal spatula.
My trick though is that I have a cast iron only for eggs... if I cook other stuff in it the smooth buttery coating gets lost and the eggs start sticking again. After a few days of eggs-only it becomes nonstick again.
I did actually polish this one, and to be fair it works mostly OK in that I'm not scraping the eggs off with a metal spatula, but it still sticks enough to be annoying, and for a teflon pot to be a measurably superior solution.
I haven't played much with preheating though, I'll have to try that - thanks for the suggestion :-)
I think you will be surprised how well stainless works when it has thin layer of fresh oil and preheated to the right temperature such that it passes the "dancing drop" test.
Really? I fry eggs in a cast iron pan almost every day, with just a little cooking spray or wipe of oil (like, put a little oil in, wipe it out with a paper towel, painting the whole surface with oil in the process). I mean, it's not no oil, but it's far from copious amounts.
Stainless is can do the job too, but temperature and shortening is even more important. There's a much tighter window of temperature that it works at. You do the "water drop test" to determine that it's ready. See youtube for an infinity of videos on how to check the stainless is at right temperature!
I've given up on non-stick pans. They're semi-disposable because the don't last very long and you don't want to use them at high temperatures. All it takes is a little bit of skill to never have to use non-stick teflon pans.