You can use dried mushrooms or a mixture of both. Dried mushrooms add an intense flavor and umami taste to the risotto as well as a darker color. If you are using dried mushrooms, boil them for a few minutes and let them soak in hot water for another 15-20 minutes or until softened. Drain and roughly chop them when they are softened and sauté them with butter for making the base of the risotto. Keep the water you soaked the dried mushrooms in and add it to the stock when cooking the risotto for extra flavor.