How a frying pan is cast and milled.
3:00 source video:
I'm still a little hesitant about those vaguely-defined "coatings". Although to be fair, it's like saying that "processed" food is bad - it depends on the process! For example, enameled cast iron cookware has a coating on it: enamel.
Of course, it's still hard to beat plain old cast iron, especially if you are carefully seasoning it like in this Virtually non-stick cast iron cookware post by Frank S.
Lead sheet casting
Casting a giant propellor GIF
video of WWII German military helmets repurposed into colanders
Milling interlocking rings GIF