Teenage daughter wants to know what Irish and/or British foods (or brands of food) to try while traveling in Ireland?

Boiled Bacon and Cabbage, with Parsley SIce
God .. I still miss it!

I've been to Ireland, and my favorites ended up the simple things: hot teas, the blended veggie soups (I went in January), the brown bread and butter. I preferred the hard ciders available on tap to the Guinness (not as much a beer drinker).

The breakfast foods in Ireland were among our favorites. Long cooked steel cut oats with cream and fresh fruit, and especially Irish brown bread. With butter, jam or smoked salmon. We also had Indian food in Dublin and seafood in some areas, but were surprised how hard it was to find fresh seafood to cook in our rental house in Connemara in Western Ireland. Apparently a lot is shipped out to other EU countries. In Dublin, a fun place that is not Irish food, is Wagamama. It's a Pan Asian noodle chain all over Great Britain and is relatively inexpensive and popular with younger people.

This may sound surprising to the unfamiliar, but seek out curry. It won't be hard to do and it's amazing and definitely "modern British" cuisine. I had really good summer pudding and drank as much tea as I could. Avoid coffee unless she knows it's French Press, as most that is served is instant.

Guiness!
After that langoustine, salmon, prawns. The seafood is spectacular even if the presentation isn't. I recall being served (in Lahinch) salmon with three types of potato.

Make sure to have some good Irish butter on either wheaten bread, soda break and/or grilled/griddled potato farls! I find most of the Cadbury sweets too sweet, with one notable exception: the Bournville Old Jamaica Raisin and Rum Dark Chocolate.

-A proper Irish/English breakfast! Black and white pudding, beans, a roasted tomato, bacon (English), and eggs.
-Sticky Toffee Pudding
-Colcannon
-Guiness & Beef or Rabbit Stew
-Sheppard's Pie
-Lamb is always a good choice (she'll know it is local after an hour of driving around the country)
Also, depending upon where she is in Ireland, there is outstanding seafood. If she is in a place like Dingle, just go with seafood! When I visited, I was pleasantly surprised by the delicious food.

This site might help:
http://goodfoodireland.ie/

Not too familiar with Irish foods, but they have (in coastal areas) some beautiful high-quality seafood (e.g. salmon). If the full Irish breakfast is anything like the English breakfast, I would seek that out. Irish dairy, like their cheese and butter, is incredibly good. Cashel blue and Dubliner are some of my favorites, served with some good soda bread. And of course, she should check out Guinness. I'm not a beer person by any stretch, but I really like Guinness and anything made with Guinness, both sweet and savory. If she's 18 or older, of course ;)

For my British food list, which is much more extensive than the Irish list:
-Chip Butty (a glorious french fries sandwich)
-Bakewell Tart
-Bangers & Mash
-anything Cadbury (yes, you can get some Cadbury sweets here, but there's more variety across the pond), for example, Flake.
-Millionaire's Shortbread
-Smarties
-Damson jam
-Gooseberry jam
-Chocolate Biscuit Cake
-Eton Mess
-bacon (way way better than any bacon in the US)
-Pimm's Cup (again, she will have to be at least 18)
-strawberries & cream
-cream tea
-kedgeree, not sure if this is British or Irish, but it's a curried rice & smoked fish dish that is often served for breakfast (?). Yummy yummy goodness and a great way to start your day.
-meat pies

Wow, now I'm hungry and itching to go to London. Hope she has a great trip!