Bring the beef broth to boil.Once it comes to a boil, reduce the heat to very low.
Cook the onions in olive oil and butter. Over low heat. About 1-2 minutes.
Add the rice. Cook for 1-2 minutes.Add the wine and let it evaporate, stirring.
Pour in a ladleful of broth.When the broth is absorbed, pour a ladleful of broth again.Add saffron on the way. Mix well.Add the broth again. Mix well again.Repeat.※It is about 15 minutes after pouring the first broth.※Or until the rice becomes al dente and thick and creamy.※Also, reserve a ladleful of broth.
Turn off the heat.Add the reserved broth, butter and Parmigiano-Reggiano. Mix well.Add salt, if necessary.Cover and let stand for 5 minutes.Finish.
Video
Notes
※Recipes and the quality of the rice used vary.※In Italy, there are many recipes that use beef marrow as well. However, I left this out because the sale of beef marrow is prohibited by law in Japan, where I live.