As tatsxxx11 suggests try feeding 2 times per day if you are currently feeding 1 time, keeping the total amount the same.

Try to notice whether the regurgitated food has other unexpected things in it like leaves, wood, bugs, rocks etc. Labs will eat anything that doesn't try to eat them first! If this was a constant condition then you would want the Vet to explore whether there was an absorption problem (i.e. insufficient digestive enzymes). Since this is a sporadic occurance it could be excessive stomach acid building up prior to the meal, with an acid blocker being the solution. Most young dogs will grow out of the stomach acid problem.

Reflux can occur in dogs, and as mentioned Reglan (Metoclopromide) can help. It's main mechanism is to accelerate the emptying of the stomach before it back flows. Of course this accelerates the emptying of the intestine also possibly resulting in soft stools in some cases. In cases of reflux sometimes the simple cure is to just raise the dish off the floor for an elevated feeding.