You cover the pan with a fat, overheat it, and the fat polymerizes : https://www.seriouseats.com/how-to-season-cast-iron-pans-ski...
Heck, I've done it on aluminum pans and eggs are fine, just like old-school breakfast spots and their griddles.
If you're cleaning it hard enough to remove the brown/black layers that form near the bottom - you're cleaning way too much, and never letting it build up a layer of seasoning.
Despite the claims that modern soap won't hurt, I find it varies tremendously by brand. So I don't use it.
I literally just drop about a tablespoon of salt into the large skillets, and wipe out with a paper towel while it's hot still.
The egg pan gets a light scrub with a non-scratch sponge, and that's basically it.
Also - I'm in no way affiliated, but this is basically the best cleaner for cast iron you can get: https://www.amazon.com/Ringer-Original-Stainless-Cleaner-Pat...
While that is generally the advice, in my experience you're much better off treating them somewhat carelessly. The main thing is to not clean them too much, and to not let them stay wet. The seasoning happens with regular use. With a new pan you want to let it stay on the heat a bit after use so the oil has some time to stick to the pan properly. After the third or fourth time using it it should start getting pretty anti-stick, until then just use a metal spatula to dig stuff out of the pan.
If food starts sticking to it, spread a thin layer of oil on it and then oven cook at the highest temperature you have.
You shouldn't use soap on the pan, that will remove some oil. Most soap won't remove the seasoning, but maybe lots of soap and excessive brushing will and food will start sticking quicker!
Once you're done with the pan drop some hot water in it (ice cold water could crack the pan) and scrape off the food - which should come out nicely. If that doesn't work or you left the pan dirty from the previous day, pour water and scrub a bit harder until smooth. Salt can help as well.
To make sure you dried it correctly, put it back on the stove and (optionally) rub some oil into it.
All true, but if you're steelmanning it, you really need to mention the weight. Also it doesn't conduct heat well.
It's heavy. The handle gets really hot.
my 12" stainless pan is hefty but not heavy. the smaller cast iron 10" or 11" is about twice the weight. I use it to cook just about everything. I think once the coating on my nice 12" non-stick pan goes off I'd probably get a carbon steel one (if it does... you can prevent most of it by not cooking things too hot and i mainly use it for hashbrowns on about medium.)
And still cheap! Slightly more expensive than cast iron, but not much; an entirely usable Lodge carbon steel pan is $40 on Amazon. The silicone handle cover is an extra $12.50 (although you don't reeeeally need one if you don't mind wearing oven mitts).
Personally I ditched nonstick coated pans — sure, PTFE is supposed to be safer than the old Teflon formulations, but the chemical used to replace PFOA in many formulations is GenX, which recent EPA studies indicate is probably similarly bad [1]. Carbon steel and cast iron just avoid all of that.
1: https://www.epa.gov/chemical-research/human-health-toxicity-...
Lodge is pretty good though IMO.
The handle does get hot, but it takes a LONG time. I can easily cook a couple eggs, or make a few grilled cheese sandwiches without any problem.
Cooking a whole batch of pancakes is too long through - I need sleeve/glove after about 25 minutes. Even then, though - it's not "burn me" hot, it's just uncomfortable to hold for more than a few seconds.
Still, never trading. If I manage to reproduce, my offspring will be the fourth generation to own and love the 10" Wagner skillet I got from my grandmother.
Slightly heftier than stainless and much easier to season. I have a set of stainless (relatively nice triple clad Cuisinart) and I still much prefer the carbon steel pans.
It's essentially what cast iron pans would be if we had better manufacturing techniques, and they work really well.
Backing up though - I would 100% take cast iron over just stainless (in every situation except a professional kitchen) and there's not much that would entice me to buy a non-stick pan, basically ever, at this point. The only thing they do ok is eggs, and a tiny egg pan in cast iron does basically the same without ever needing to be replaced (or giving me liver cancer).
Cast iron isn't hard to use, is indestructible, has a very low chance of poisoning me (and handily helps provide iron in my diet), and just makes things brown like nothing else I've used - nothing will make hash browns or a grilled cheese sandwich like cast iron.
Plus it's dirt cheap (less cheap is carbon steel, but again - very nice).
What's not to like?