I agree with great reply from RebeccArmstrong
When you recall your dog for the recall use his name and straight after use the word "come". Taht is the command he has to follow.

I always say "Dude COME" and hold my arms out wide as if welcoming him for a hug, as he draws nearer i bring my arms down to my front and reward him with a treat once he is sitting in front of me, facing me.

He knows through the training stages that there is a treat in my hand so he will follow my hands to his final sit position. After he has got the idea lose the treats but still praise loads and loads

It is all down to practise, patience and lots of rewards. Do not tell him he is a good boy if he does not come all the way back to you and is not sitting in front of you, as he will mistake that behaviour as a good one for the praise your giving him.
Make it fun so that he wags his tail and enjoys it when he returns to you.

Use a long lead and if he does not pay attention to you because he is sniffing about, give the lead a few tugs to get his attention.


Stick with it it will come.
It took me a while with my lurcher but boy was it worth the wait.

Praise and reward praise and reward.