What is this?

I think it's meant to diffuse, or lessen, the concentration of heat from a gas burner. I don't know if it would work with electric. You put it between the burner and the pan.

My parents had one, that I have around here ... somewhere. I used it once, but I can't recall what I was cooking. I think I needed a certain level of flame, but was concerned that the dish was to delicate, and might burn.

I'm going to dig is out, and start heating tortillas on it. Great idea.