This hearty casserole calls for garbanzo beans instead of tuna--a surprising but wonderful substitution--and sliced mushrooms instead of the traditional can of dairy-and salt-heavy Cream of Mushroom soup. Tu-no Casserole Prep time: 30 mins Cook time: 52 mins Total time: 1 hour 22 mins Serves: 8 to 10 (makes 7.5 cups) Ingredients [b]For the casserole:[/b]