From my mom.
50g unsalted butter
1-2 onions (white or red, both work)
400g risotto rice
250ml dry white wine (I usually use Riesling)
1l beef broth
1-2 hands full of shreeded parmesan
a pinch of saffron (optional, only for color)
Finely dice the onions.
Melt the butter in a pot. Add the onions and cook into glassy. Add rice and briefly roast. Add wine and let cook until wine has been soaked up. Add a bit of salt and a good amount of pepper. If you want to add saffron, do it now by adding it to a bit of the broth.
Over the course of 20min under constant stirring, add the broth. Just add a bit and let soak up fully before adding more.
At the end, mix in parmesan, give a moment to melt, then serve.