I don't know about sandwiches, but they have my favorite, Lefsa, there. It is a traditional Norwegian treat, it's a very thin potato pancake that has butter and sugar on it and rolled up, think of a crepe.
My grandmother and dad are full blooded Norwegian and I grew up eating this...I was so happy to get some from the bakery when we were there!
You can also get it at Askerhus, if you ask for it at the table.