My own idea for adding two additional ingredients to my turkey tetrazzini:
Dry cranberries and raisins? If it is a good idea that is recommended by Food52? How much quantity is recommended to add the dry cranberries and raisins to the receipt?
Mix all of the casserole ingredients except the fruit. Then take a small bit & add some fruit & try it. If the mixed casserole has raw ingredients you microwave the bite before you eat it. Then decide whether to add them to the whole casserole