Earlier in the year I planted Little Gem in a flower trough.I cut off the lettuce and left the stems.
I totally neglected them but recently they have started to produce new leaves.
Is this normal?
Yes, you normally get a few new plants growing around the edge of the old stem.
I have never actualy got the new plant to grow big enough before it has bolted, so don't know if it is worth saving them or not.
If you harvest them at baby leaf stage (2 to 4 inches), you can normally get them before they bolt.