There's a very cheap Lithuanian version of Parmesan called Dziugas which is in my opinion better than a cheap Parmesan
I picked some up today at Auchan - looking forward to tasting it. Thanks for the suggestion.
Gruyere is worth every zloty when you're making french onion soup. Nothing else comes close.
I'm a novice at preparing FO soup - perhaps when I master the recipe, I'll splurge for gruyere per your suggestion.