Bring broth just to a simmer over medium heat.
Heat oil in a large pot over medium heat. Cook onion with salt, stirring frequently, until onion is translucent and soft.
Add 1/2 cup of broth and cook, stirring often, until liquid evaporates and onion is tender.
Add rice to onion and stir to coat with oil. Cook, stirring constantly, until rice becomes slightly translucent around the edges.
Add wine, bring to a simmer, and cook, stirring occasionally, until liquid has evaporated.
Reduce heat to medium, than add hot broth in 3/4 cup increments, stirring constantly and allowing liquid to absorb fully before adding more, until rice is al dente and surrounded by liquid. Take care not to overcook.
Remove form heat, add butter, and stir until melted. Gradually add most of the Parmesan, stirring until melted. Stir in additional hot broth if needed to achieve the right consistency. Adjust salt and serve with remaining Parmesan and black pepper.
Made using home-made turkey broth, diluted with some water; pinot grigio; koshihikari rice; and sweet-cream butter. Didn't end up using all of the both, only about 9 cups of it. The consistency was pretty loose, and I think I overcooked the rice somehow, even though it was done much faster than indicated. Overall, very good, but definitely needs the salt adjusted at the end to compensate for the variability in the broth, butter, and cheese.
Made this again, and again it did not use the full amount of broth or fully cooking time. It used perhaps 6~7 cups worth of broth and not quite 30 minutes. It may be the cooking it at a higher than intended temperature, which I may have done, causes it to cook faster and ultimately use less broth. Either way, it's very good, though a bit oily once the Parmesan is added.