For the mushrooms, wipe clean with paper towels. Remove the stems (only for shiitake and cremini) and reserve the stems for broth. Slice the mushrooms into ¼-inch strips and set aside.

In a small pot over medium heat, combine the vegetable broth and mushroom stems. Bring to a simmer. Reduce to low heat to keep hot.

In a large heavy pan over medium-high heat, heat the 1 tablespoon butter and ½ tablespoon olive oil. Stir in the onions and cook until soft and translucent, about 5 minutes. Add 2 chopped black garlic cloves. Stir for 1-minute. Add rice and stir continuously until fragrant, about 3 minutes. Add the white wine and cook until all liquid almost evaporated. Reduce heat to medium, add ¾ cup of vegetable broth. Season with salt and pepper. Cook and stir until most of the liquid is absorbed. Add another ½ cup of broth and stir until most of the liquid is absorbed. Repeat this process until the risotto is creamy and the rice is al dente, about 20 minutes.

Meanwhile, in a medium pan over medium heat, heat the rest of the butter and oil. Add the mushroom and season with salt. Cook and stir occasionally, until the mushroom are slightly golden brown, about 10 minutes. Turn off the heat and set aside. Season with more salt if needed.

Back to the risotto, add the cooked mushrooms. Stir in the mascarpone, parmesan cheese and 1 chopped black garlic clove. Season with salt and pepper and adjust to your own taste. Transfer to servings plates. Top with extra parmesan cheese and chives. Serve immediately.