The jokes on me with this one. I do a bit of magnet fishing and have two others similer to this, both a bit smaller.
This one is a xmas prezzie from one of my daughters. She wanted to see how good it was and I duly obliged by
attaching it to the underside of the frying pan (non stick)

I have tried sliding it off which is the usual way
to get them off,not this one. I have even put a breaker bar through the ring to try and prise it off, no luck. If
I do not get it off there will be no bubble and sqeak this week at all. Ant suggestions will be greatfully received

I do not want thanks for any research I am able to help out with. I just love doing it.