Begin by heating the broth in a medium saucepan over low heat.
In a large skillet, heat the olive oil over medium heat. Add the sliced mushrooms and cook until they release their moisture and become golden brown, about 5–7 minutes.
Season with a pinch of salt and pepper.
Remove the mushrooms from the skillet and set them aside.
Using the same skillet, add the chopped onion and cook until it becomes translucent,, about 3–4 minutes. Add the minced garlic and cook for an additional minute
Add the Arborio rice to the skillet with the onions and garlic. Stir constantly for about 2 minutes.
Pour in the white wine and stir until the liquid is almost completely absorbed.
Begin adding the warm broth one ladle at a time, stirring constantly.
Wait until the liquid is almost fully absorbed before adding more broth. This process takes about 20–25 minutes.
Once the rice is al dente and the consistency is creamy, stir in the sautéed mushrooms. Cook for another 2–3 minutes to allow the flavors to meld together.
Remove the skillet from heat and stir in the butter and grated Parmesan cheese. Taste and adjust the seasoning with salt and pepper if needed.