What is my Paella Pan made of? I bought a paella pan at a flea market. I have no idea what metal(s) it's made of. It cooks like a nonstick but doesn't have a commercial nonstick coating. I clean it by washing it with dawn and hot water and dry it completely. The nonstick-ness survives the washing method. There is no stamp on the bottom.

1) How do I tell what my paella pan is made off?
2) Is it ok to continue to wash it without knowing what it's made of?

I often use it to sear steaks and then place the pan in a 420°F oven to finish cooking
3) is this safe to do?
This kind of pan is traditionally made of blue steel. The coating on it would be a homemade seasoning from oil. 

I cannot tell it 100% from just the small picture, especially since there are manufacturers who sometimes imitate traditional looks while using different materials, but this is the likeliest guess for this pan. 

If it is indeed a seasoned blue steel pan, then the seasoning can take any temperature at which food is cookable. If you take it so far that it burns off (which would take something around 500-600 Celsius, so unlikely to happen in a home kitchen) you can replace it yourself, although you might need a few tries until you get it right.