Well there are loads of different ways but this one works for me.
Virtually guaranteed in my experience - if he's at all interested ...
This method WORKS if done properly ...
I wait until evening as they're nocturnal of course . I let the rodent thaw out in the reptile room so they get the smell .. Then put a couple of pieces of card over the substrate ....
Then I warm up the mouse / rat with a hairdryer and offer with tongs IMMEDIATELY whilst still warm . If refused simply repeat the heating and offering as many times as needed. .
A couple of mine will only strike feed from within their hides so I dangle the warm rodent in front of the hide's entrance - usually works but if it fails simply reheat the rodent with a hairdryer and immediately offer again whilst it's still warm , continue until it's grabbed ...
I always wait until evenings to feed as they're nocturnal of course .
Incidentally , if it shows no interest at all not even a tongue flicker maybe it's best to leave for a week or so.