Heat the chicken or vegetable broth over low heat in a medium saucepan. Keep it warm throughout the cooking process.
In a large, heavy-bottomed saucepan or skillet, melt half of the butter over medium heat. Add the chopped onion and cook until it becomes translucent about 3-4 minutes.
Add the minced garlic and cook for an additional 1 minute, stirring constantly to prevent burning.
Stir in the Arborio rice, ensuring each grain is coated with butter. Cook for 1-2 minutes, until the rice becomes slightly translucent around the edges.
If using wine, pour it into the saucepan and stir until it is absorbed by the rice.
Add the warm broth to the rice, three-quarters of a cup at a time, stirring constantly. Allow each addition of broth to be absorbed before adding the next. It takes about 2 minutes for each addition of water to be absorbed.
This process should take about 20-25 minutes, and the rice should be tender but still slightly firm to the bite.
Once the rice has reached the desired consistency, remove the saucepan from the heat and stir in the remaining butter and Parmesan cheese—season with salt and freshly ground black pepper to taste.
Allow the risotto to rest for a couple of minutes before serving. This will help it to thicken slightly and become creamier.
Serve the risotto in bowls, garnished with chopped parsley if desired