Sandwiches
I agree, freshly made sandwiches is a good one.
Norwegian food
Whale meat and fish cakes? I don't think so but then again Ikea is packed full of people for the Swedish food but I think that has a lot to do with the price. And money is probably why so many are in Norway too ;0)
remiras, I recommend that you also take into consideration where you are going to set up shop, for example, is it mainly a residential area - restaurants , offices - lunch break, Tourist area - traditional polish food.
Good luck