Does he go quite a few hours between meals? For instance -gets breakfast about 7am (ish) and dinner about 5-6pm?
Does he cough up/vomit up each time when a meal is due?
And he's perfectly well and happy otherwise?
There's nothing wrong with that but there can sometimes be a build up of stomach acid just before they are due to eat. If you think that might be it, then splitting the food into 3 meals a day might help.
But obviously that might not be the answer, so do mention this to your vet if it keeps happening.