If there's a cupboard door anywhere near where he eats, try shutting it gently as he begins to eat the first night, then progressively louder at each successive meal. If he seems nervous at any point, then don't make it louder next time, instead go back to what he'll tolerate.
We broke Grace of her fear of her metal bowl by plunking it hard on the floor in front of her while she's waiting to eat. Eventually, she began to associated eating (something pleasant) with the clanging and is no longer fearful of her bowl.