One of the foundations of many, many casseroles is a can of cream of mushroom soup. Condensed canned soups leave much to be desired in taste and also contain many processed ingredients. If your goal is to cook with real food, but you have recipes in your repertoire that call for cream of mushroom soup, then I encourage you to try and make your own. It only takes about 15 minutes and the flavors in your dish will increase ten-fold.
This is the perfect dish that will please almost anyone, but with extra depth of flavor. The casserole keeps very well in the fridge and can be made a day ahead of time and then heated in the oven before serving.