Argh searched and was a video on a type of bezel setting but for a faceted stone. It was like a peekaboo bezel setting where the jeweller carved a notch into the thick bezel and kind of snapped the stone in.

I've got my mind set on trying my hand but wanted to give it another look before I tried.

The jeweller used a heart burr to carve out the notch.

Can anyone remember it? I've searched high and low on youtube and here but I don't know if it has a specific name for the technique.