Sometimes it's worth stating the obvious, Am :)
I have a Polish couple coming over for afew days and would like to cook for them.
my suggestion would be duszonki (ziemniaki duszone)..i'm a paddy and the wife makes it for me and i love it and any poles i know love it too..all you need is a big pot, a little oil in it, sliced potatoes, carrots, mushrooms, onion and a good flavoured polish sausage, any kind will suffice, crack some black pepper and a pinch of salt for seasoning. you can add other vegs if you like, onion,red or green pepper or yellow for that matter. as i said a little oil in the bottom of the pot and start layering everything in spud, carrot, mushroom, sausage etc etc. fill the pot to the top cover well and cook on a low heat until you can stick a needle easily through the top layers..bottom layer may get slightly caramelised if cooked on too high a temp but if your friends are anything like my mrs they'll love the burnt bits too..i know i think its delicious so maybe give it a trial run before your pals arrive. hope this is a help
As I said, simplicity is genius. That's a simple dish that can't go far wrong :)