Place a large skillet with a heavy base over high heat. Add the olive oil and when it heats up, sauté the onion for about 2 minutes. Add the mushrooms and continue to sauté for 10-15 minutes, until all the liquids have evaporated.
Add the rice and stir for 30 seconds, making sure each grain is coated with oil. Pour in the white wine and let the alcohol evaporate. Lower the heat to medium and add one or two tablespoons of hot broth. Stir with a wooden spoon until the rice absorbs all the broth.
Then, gradually add the broth and stir until the rice becomes al dente, about 15-20 minutes. Taste to check if the rice is ready, then add the butter. Stir until the butter melts and add the parmesan cheese and parsley. Mix very well until the risotto becomes creamy. Taste and season with salt and pepper.
Divide the risotto into four plates, garnish with fresh parsley leaves and, if desired, drizzle with a little olive oil.
Note: We can use whatever mushrooms we like. White mushrooms, oyster mushrooms, porcini mushrooms, etc.