Prepare the vegetable stock and add the saffron threads. Heat 1 tbsp butter and 1 tbsp olive oil in a large pan over medium heat. Add the onion and black garlic and fry until they are getting soft. Add the rice to the pan and stir well to coat the rice with the butter and oil. Fry the rice for a few minutes until it is glassy. Deglaze the rice with the white wine. Now add a large spoon of saffron stock and stir until the stock is almost absorbed. Repeat this process over and over until the rice is cooked and creamy. This takes about 20 minutes.
In the meantime, heat the rest of the butter and olive oil in another pan and fry the shiitake until they are light brown.
Add the cooking cream and grated Parmesan cheese to the risotto and stir until the sauce is nice and creamy. Season with salt and pepper. Serve in deep plates and serve with the shiitakes and some Parmesan cheese.