Here are 2 reposts of previous recipes for homemade 'cream of' soups

Homemade "Cream" Soup
Author: girl_chef
Date: 1998/11/05
Forums: rec.food.cooking

To use in place of canned cream soups in casseroles or as a base for your own soups. Much lower in fat and salt than the canned versions. The trick is to have it made up ready to use!

2 cups powdered nonfat milk
3/4 cup cornstarch
1/4 cup (or less) instant vegetable boullion
2 tbsp. dried onion flakes
1 tsp. basil leaves
1 tsp. thyme leaves
1/2 tsp. pepper

Combine all ingredients, mixing well. Store in an airtight container until
ready to use.

To substitute for one can of condensed soup:

Combine 1/3 cup of dry mix with 1 1/4 cups of cold water in saucepan. Cook and stir until thickened. Add to casserole as you would the canned product.

Makes equivalent of 9 cans of soup. Vary the spices to suit your own taste or the type of casserole you were making.

Yield 9 servings with less than 1-gram fat per serving.

Variations:

Mushroom Soup: Add 1/2 cup finely chopped mushrooms
Celery Soup: Add 1/2 cup minced celery
Potato Soup: Add 1 cup diced potatoes, cooked
Vegetable Soup: Add 3/4 cup mixed vegetables, cooked
Broccoli Soup: Add 1 cup chopped broccoli, cooked
Asparagus Soup: Add 1 cup chopped asparagus, cooked

Creamed Soup Base/substitute
Posted By: kt/mn
Date: December 30th 1999

This recipe is the equivalent to 1 10 2/4 oz can cream of chicken soup. The recipe may be doubled, but still use only 1 egg yolk.

Creamed Soup Base

1 1/2 cups chicken broth
4 Tbsp. flour
2 Tbsp. butter
1 Tbsp. cream
1 egg yolk

In a small saucepan, heat broth 10 minutes. Melt butter and stir in flour to make a roux. Whisk roux into broth. In a small bowl, blend together cream & egg yolk. Gradually add 1/4 cup of broth mixture. Pour contents of bowl into saucepan. Cook and stir for 10 minutes. Do not boil.

Yield: 1 1/4 cups