Have you tried cutting his food up even smaller. and only allowing him to take the next bite when his mouth is empty? The best way to teach is by example. Let him see you eating properly. I would NOT make a big issue of this. It only reinforces the habit. Has he been sick in recent weeks, or is he cutting molars again? Does this happen in a specific meal or in ALL meals? What exactly is “forever?” Is he simply dawdling over the meal for some reason (i.e., avoidance of bedtime)? Have you spoken to the pediatrician about this?