Again, drop back to basics in training, put him in a situation where he can't reach the food ( set him up for success, don't LET him fail) and when he so much as looks at it, redirect him and reward him. Again its an incremental process and gradually you should be able to get him to walk right past the food-in reach- and continue his search.
The key is not letting him fail by your actions, and rewarding him like crazy for his.Too many folks trust the dog too much too early. Put him in a position ( out of reach) where he can't possible fail. As the increments close in, if he pays more attention to the closer food than he did last time...back up a couple steps in your training to where he was doing it right.
