There were these little potato pastries that we kept seeing in the grocery stores that seemed to be very common and rather popular:
Eventually we actually remembered to buy a few of them and took them home. They were in fact, not potato. Or at least not most of them. We looked up the words for them and it turns out that they were a mix of different ingredients (mostly not potato).
The light one on the top left was actually filled with rice, the orange one on the top right was carrot, and the one on the bottom was a sort of buttery potato. They are, in general, called Karelian pastries, coming from the region of Karelia. What we thought were potato skins are actually made of different types of flours which are then rolled out and then stuffed with various (mostly grain/carb) fillings. Pretty tasty, though not at all what we expected.
The rice one was the traditional Karelian filling - not seasoned almost at all and rather plain. The carrot one was actually not much like carrot and reminded me a lot of Spanish rice Rice a Roni, if you've ever had that before. And the potato one was like really buttery mashed potatoes - very smooth.
More mysteries solved at the grocery store, though so many more to unlock. :) There is a wealth of things I am very excited to try at the deli counter. Slowly beginning to recognize some of the common words that are floating around (limppu = loaf, vesi = water, maito = milk, voin = butter, etc). Not too shabby.