How can I teach my dog to free eat?

[Brandi-Jo]

I have a 4 1/2 month old jack russell puppy and i know we feed her enough, but at every meal, when i put her food in her bowl, she barely chews and mainly just swallows it all because she is eating so fast. We have tried leaving the room and she still does it. Does anyone have any ideas? I would really like to be able to just have food in her bowl and her eat when she is hungry, but even if not, at least have her slow down so that she chews her food. Thank you all in advance