Thanks for the suggestions.
Done the repair this morning.
I used an M5 Jack Nut with a screw. Not quite as easy as I had thought it would be but as the Jack Nut rotates in the hole.
As this oven cavity had a 10mm hole with a slot running through it I was able to put a small slotted screwdriver through into the side of the Jack Nut to prevent the rotation. After fitting, I put a small self tapper into the slot next to the Jack Nut to prevent it from rotating in the future should it have to be undone.
The only thing I would do differently in the future is use a longer bolt with a nut to pull the Jack Nut down into the panel then fit the element in place with a shorter bolt.
Otherwise, this makes a very tidy repair.