As soon as your spaniel has stopped and is looking to see where you are, call his name, blow the recall whistle or whatever command you normally use, then turn and leg it – run away from him.
Chances are your dog will just stand there trying to work out what is going on and why you are running and not chasing him – this is not what normally happens.
Stop again and repeat your recall of him and then run away again.
Eventually he will come looking for you and there is every chance that he will come speeding up to you and then run past – as there is still a chance that you’ll chase him again.