Put a couple of clean golf balls in his food bowl. He'll have to slow down his eating if he has to eat around the balls and then lick all of the food off of the balls.
Thankfully so far he's keeping it down, and when it did happen it wasn't that frequent, just scary (didn't think it would happen so suddenly), as it only happened twice. His food was also obviously not chewed as they looked pretty whole from just first glance. You'd think he'd just dragged his food around the house.If it's happening fairly frequently then I'd get him to a vet. It could just be him eating too much too fast but it could also be something more serious. Better safe than sorry.
I wish I had paid more attention when Ziggy was vomiting. Looking back, I think it might have been the beginning stages of his cancer. We always want to think it's nothing serious, but sometimes it is.