Heat the chicken broth in a saucepan and keep it warm over low heat.
In a large skillet or saucepan, heat the remaining oil over medium heat. Add the chopped onion and cook until softened, about 3-4 minutes.
Add the risotto rice to skillet and mix with onion. Toast the rice for 1-2 minutes, stirring constantly, until it becomes translucent around the edges.
Pour in the white wine and cook until it has evaporated, stirring constantly.
Begin adding the warm broth to the skillet, one ladleful at a time, stirring frequently. Allow each addition of broth to be absorbed by the rice before adding more. Continue this process until the rice is cooked al dente, tender with a slight bite, about 18-20 minutes.
Just as the rice is done, mix in reserved mushrooms.
As you are ready to turn off the heat, add whipping cream and stir quickly to incorporate it into the rice. This should take just 1-2 minutes.
Off the heat stir in the grated Parmesan cheese until melted and creamy. Taste and adjust seasoning with salt and pepper if necessary.
Remove the skillet from the heat and let the risotto rest for a minute or two. Serve hot, with your favorite protein, if desired. A slices of pan-fried chicken works remarkably well with this risotto.