When it's done, the centre should have a slight wobble.
The Sun
It's ready when it has risen slightly and only has a very slight wobble in the middle.
The Sun
Bake for 25-35 min until risen with a slight wobble.
Times, Sunday Times
There was a slight wobble with just one win in eight games at the turn of the year.
The Sun
Pour into the shell and bake for 50-60 minutes or until set around the edges (the centre will still have a slight wobble).
Times, Sunday Times