No, this isn’t a cast iron thing. Using stainless pans, you can get nonstick effects that, in my experience, far outperform Teflon anyway. The process is called “spot seasoning.” I have cooked crispy, cheesy rice noodles with eggs with zero sticking.
I love my cast iron pans, but stainless is my daily go-to. Added bonus: use 100% copper wool to clean your stainless pan. The copper-coated wool at most grocery stores is problematic; you might get a few uses out of the coated garbage and then it starts shedding metal bits.
I didn’t know about this technique, thanks!
You can also season the whole pan once and the nonstick effect will last a very long time.