In a large pot, heat the chicken stock and keep warm over low heat.

In a large pan, melt 2 tablespoons of butter with the olive oil over medium heat. Add the onions and sauté until translucent, about 3 minutes. Add the garlic and cook for another minute.

Add the mushrooms and cook until they release their moisture and become tender, about 5-7 minutes.

Add the Arborio rice and stir to coat with the butter and oil. Toast the rice for 1-2 minutes until it becomes translucent around the edges.

Add the white wine and simmer until it has completely evaporated.

Add 1 cup of the warm stock and stir until absorbed. Continue adding stock, 1/2 cup at a time, stirring constantly and allowing each addition to be absorbed before adding the next. This should take about 18-20 minutes in total.

When the rice is tender but still firm to the bite, remove from heat. Stir in the remaining butter, Parmesan cheese, and parsley. Season with salt and pepper to taste.

Let the risotto rest for 2 minutes before serving. Garnish with additional Parmesan cheese if desired.