1/3 cup freshly grated Parmesan cheese, plus more for serving
fresh chopped parsley for garnish
Heat the butter and olive oil in a heavy-bottomed saucepan, preferably about 10 inches in diameter. Cook the leek until tender, 5-7 minutes. Add the mushrooms and continue to cook until soft, another 5-7minutes. Pour in the wine and cook until it is mostly evaporated.Add the rice and stir for 2-3 minutes, ensuring the grains are thoroughly coated in oil.
Pour in one cup of the broth along with the salt. Bring to a very low and gentle simmer (do not let the risotto boil at any point), stirring constantly, until the rice has absorbed the broth. Add another cup of broth and repeat the process, adding one cup of broth at a time, ensuring the rice has absorbed the liquid before adding the next cup of broth. (The rice is done when it is tender but still slightly firm. Do a taste test to determine doneness and whether additional broth is needed to continue cooking.)
After last cup of broth has been added and is absorbed, remove the risotto from the heat and stir in the 5 tablespoons of butter and Parmesan cheese. Stir until the rice is a nice creamy consistency. If you prefer a"soupier" consistency, add a little more broth. Add more salt to taste.Serve immediately sprinkled with some extra grated Parmesan cheese and fresh chopped parsley.