Leek and Mushroom Cannelloni is a delicious vegetarian dish that combines the earthy flavors of leeks and mushrooms with creamy ricotta cheese. The leeks and mushrooms are sautéed until tender and then mixed with ricotta, Parmesan cheese, and herbs. The mixture is then rolled up in lasagna noodles and baked in a rich tomato sauce. The result is a comforting and flavorful dish that is perfect for a cozy dinner.