Butter is your friend - if you use parchment, make sure to butter that too.

I wouldn't think of using a non-stick pan. The cast iron skillet works perfectly. I melt some butter or coat the bottom of the pan with olive oil before I add the egg mixture and the frittata comes out perfectly, golden brown.

Why not line it with parchment paper?

If it is perfectly seasoned, it prob won't stick, but just in case, use extra oil or butter