Realistically, we don't always have time to whip up a sauce from scratch, but if we still want to use something we have made, there are some solutions.
1. Make a pantry mix ahead of time. This can be stored in an airtight container for a few months. Here is a recipe from the cookbook, Marlene's Magic with Food Storage by Marlene Peterson:
Cream Soup Mix:
2 cups nonfat powdered milk
3/4 cup cornstarch
1/4 cup instant chicken bouillon
2 Tbsp dried onion flakes
1 tsp basil
1 tsp thyme
1/2 tsp pepper
Combine all ingredients. To make: use 1/3 cup mix and 1 1/4 cups water in a blender. Mix until smooth, then transfer to a saucepan and heat, stirring constantly until thickened. Add sauteed mushrooms, cooked chicken or sauteed celery to get the desired flavor.
2. Bottle your own soup. I did a post last year on Home Canned Cream of Mushroom soup. I have since used all of the pints I bottled and am looking for a good deal on mushrooms so I can make another batch.
To make cream of chicken or celery soup, use chicken stock instead of beef, add chicken or celery for the mushrooms.
3. You can make a bunch of White Sauce Butter Balls and freeze them. Then, when you need some cream of _____ soup, you can make some up quickly.
Simply combine 2 cups of flour, 2 cups butter, 2 tsp salt, 1/2 tsp pepper, 1 tsp thyme, 1 tsp basil. When the mixture is completely combined, use a small ice cream scoop to scoop out tablespoon sized heaps onto a cookie sheet. Freeze until solid and then put into a sealing plastic bag or other container.
To use, heat up about 2-4 balls (depending on how thick you want it) with 1 1/3 cups milk (or 2/3 cup milk and 2/3 cup broth), cooked mushrooms, chicken or cooked celery. Cook and stir until thick and bubbly.
There. If you want cream of broccoli or cream of asparagus or whatever other cream of's there are available, use your imagination and substitute.
I am not going to tell you that I don't have a case of cream soups in my pantry. They are just too convenient not to use. I am just giving you some homemade alternatives that I have used and think are pretty nifty.