Rinse the arborio rice briefly if desired
Heat a pot or pan over medium heat
Add butter or olive oil
Add chopped onion or shallot, if using
Cook until softened
Add the arborio rice
Stir for 1 to 2 minutes until lightly toasted
Add warm broth one ladle at a time
Stir frequently
Wait until most of the liquid is absorbed before adding more
Continue until the rice is creamy and tender
Cook until the center is just slightly firm
Remove from heat
Stir in butter, cheese, or other seasonings if desired
Serve immediately