You can turn this soup base into any of the cream soups below by adding the listed ingredients.
Cream of mushroom: Add 8 ounces of sliced mushrooms, browned in 2 tablespoons of butter. A splash of leftover red wine goes especially well in mushroom soup.
Cream of celery: Add 1 cup of sliced celery, steamed.
Cream of broccoli: Add 4 cups chopped broccoli, steamed.
Cheddar broccoli: Add 1 cup shredded cheddar while stirring constantly, then add 4 cups chopped broccoli, steamed.
Cream of spinach: Add 4 cups chopped, raw spinach.
Corn chowder: Add 1 pound of corn kernels, 1 red pepper, chopped, and 2 small potatoes, peeled, cubed, and browned in 2 tablespoons oil.
Seafood chowder: Add 1 cup of cooked fish, scallops, chopped shrimp, or other seafood.
Cream of chicken or turkey: Add 1 cup of cubed, cooked chicken or turkey, and 1 cup of cooked rice.
You can add a chopped onion to any of the soups by sautéing it in the butter for a few minutes before adding the flour.