There is a cafe in Beddgelert. Last time I went there they refused to do breakfast as they reckoned they did not have enough custom at that time to justify it. They do normal meals.
There is another one about 5 miles down the road near Tremadog(outside Porthmadog). I can't remember the name, but it's right on the side of the road.
There is one near the Cob in Porthmadog(Julie's?) that do breakfasts.