Okay this might be obvious to some people but nobody ever told me this growing up so maybe it'll help someone else lol
I used to throw away the hard rind at the end of parmesan blocks without thinking about it. my coworker mentioned she saves hers in a ziplock in the freezer and tosses one into soups and stews while they cook. I thought it sounded weird but tried it with a basic vegetable soup i was making and genuinely could not believe the difference. it just makes everything taste... richer? deeper? hard to explain but it doesn't taste like parmesan exactly it just tastes like the soup has been cooking for way longer than it has.
I know parmesan isn't the cheapest but if you're already buying it the rind is literally the part you'd throw away anyway so it's free flavor essentially. I've been keeping a little bag in my freezer for months now and it's made my cheap weeknight soups feel a lot more worth eating after a long day
Anyway just wanted to share in case anyone else didn't know this was a thing