Jamie Oliver's Fifteen in Cornwall is at Watergate Bay, but you could have a look around on http://www.sugarvine.com/DevonandCornwall/
I live on the south coast of Cornwall so can't really help with eating out locally
Well when i last went last june, i ate at a resteraunt called 'The Old Inn' in St. Breward nearer the Bodmin area. I believe this is a little off track from where you said but it is well worth a try, the cosy atmosphere is perfect. The chef has various awards for his food also.
I have been to fifteen in watergate bay and it was really really nice, there is also viners in Newquay too. I have also had a really nice bacon sandwich in bude but I doubt thats what you are after.