Flat spot!!!

[Sasso1]

I drive 53 plate Peugeot 206 Auto with genuine 35K miles on clock.
Occasionally when at say roundabout & intend moving off - on pressing accelerator engine races for a second or two before the car moves off.
This does not happen when accelerating on the move
Any ideas what could be the cause of this.
Your comments appreciated Sasso1

[AlBags]

Check transmission oil level .. or replace and change any filter if it's been a long time.