Warm your vegetable broth in a saucepan over low heat, so it's ready to be added gradually.
Heat olive oil in a wide pan over medium heat. Add the sliced mushrooms and sauté for 5-7 minutes until they release their aroma and turn golden brown. Remove half of the mushrooms and set aside for later.
Add the finely chopped onion to the same pan and cook for 3-4 minutes until translucent and fragrant. Stir frequently to prevent burning.
Stir in the minced garlic and cook for about 30 seconds until fragrant, filling the air with a subtle aroma of garlic and mushrooms.
Pour in the white wine, stirring constantly, and cook until the liquid mostly evaporates, about 2 minutes. This lifts the flavors and adds brightness to the dish.
Add the arborio rice to the pan, stirring to coat each grain with oil and toast lightly for about 2 minutes until the edges become slightly translucent and the rice smells nutty.
Begin adding the warm broth, one ladleful (about 1/2 cup) at a time, stirring constantly and waiting until most of the liquid is absorbed before adding more. Maintain a gentle simmer during this process.
Continue this gradual addition and stirring process for about 18-20 minutes, until the rice is creamy and just al dente—tender but with a slight bite.
About 2 minutes before the rice is ready, fold in the sautéed mushrooms that you set aside earlier, distributing them evenly through the risotto.
Remove the pan from heat, then stir in the butter and grated Parmesan cheese until melted and glossy. Taste and adjust seasonings with salt and pepper as needed.
Let the risotto rest for 2 minutes off heat, covered loosely, to allow the flavors to meld and the texture to settle into a luscious, creamy consistency.
Serve hot, garnished with extra Parmesan or fresh herbs if desired, and enjoy the fragrant, earthy, and velvety bowl of mushroom risotto.
