First step: open that bottle of white wine and pour yourself a glass.
In a small pot, bring vegetable broth to a boil. Reduce heat to low and cover. Meanwhile, in a large skillet, sauté the mushrooms on high heat until they’re golden brown. Set aside.
Reduce heat to medium and in the pan used for the mushrooms, melt butter and add the onion. Cook until translucent, about 3 minutes. Add the garlic, salt and pepper and cook for another 30 seconds.
Add arborio rice and stir to coat in butter. Add wine and stir until most of it has been absorbed by the rice.
Add 1/2 cup of broth, stirring often until most of it is absorbed. Repeat, 1/2 cup of broth at a time, stirring often to ensure even cooking and to prevent from burning.
Add the last ½ cup of broth, let absorb a little and then add the mushrooms. Stir until all the liquid has been absorbed.
If using parmesan cheese, add it to the pan and stir to incorporate.
Divide into two plates preheated in the oven and serve with freshly minced rosemary and a drizzle of truffle oil (optional, but not in my book).