Well done Steve, I bet you worked hard to find that.
It's Castell Deudraeth (deudraeth = two beaches ) in Penrhyndeudraeth and we had a delicious lunch there yesterday.
There is an offer on there at present:-
two courses for £20.00
three courses for £25.00
included with the lunch is a ticket to get into Portmeirion which is about half a mile away. The entry into Portmeirion village is normally £12.00 so the offer is good value
The weather was perfect yesterday so after our three courses we went into the village to have a look around