Cream of mushroom soup is distinctively different from thinner, brothier soups because it features a thick, luxurious consistency, thanks to the addition of cream.
It also contains a natural thickener in the form of a roux. The characteristics of these ingredients make cream of mushroom soup a compatible partner for meat and potatoes.
This makes it ideal for your pot roast because it improves the meat's flavor and texture while simultaneously reducing it into a moreish gravy while it cooks.
It also brings in moisture and flavor-amplifying glutamates, adds a softer finish and richer composition, and embraces the long-standing relationship between beef and mushrooms.