Mushroom Scalloped Potatoes (adapted from Sunset Cook Book, 1949)

Mushroom Scalloped Potatoes is a dump-and-go potato side dish suitable for Sunday dinner.  It’s a labor-saving alternative to more sophisticated sides, and while it lacks the panache of a good pan of scalloped potatoes or funeral potatoes it will still scratch the itch for a creamy, starchy side.  The recipe comes to me by way……