Something not to miss in Ireland is soda bread. It's the best bread in Europe - soft, moist, nutty and delicious. Perfect with Irish cheddar cheese. And cheap too..

I recommend stopping for Fish and Chips from Leo Burdocks opposite Christchurch Cathedral. It's not glamorous but it is one of the oldest places in the city :) It makes a good lunch, and a visit to the cathedral is also pleasant. Traditional Irish food is not very fashionable, you might struggle to distinguish it from street cafe food :)