To make a simple cream of shrimp soup, melt 1/2 stick of butter in a saucepan over medium heat, cook 1 chopped onion for five minutes, and whisk in 1/3 cup of flour, 1 tablespoon of seafood seasoning and 1/2 teaspoon of dried parsley. Stir the mixture constantly until smooth.
Gradually whisk 4 cups of milk or half-and-half into the pot, stirring constantly to blend the ingredients. Bring the liquid to a boil, and stir in 1 pound of cleaned raw shrimp. Turn the heat to low, and simmer the soup for 20 minutes or until the shrimp is pink and opaque throughout. Optionally, add 3 tablespoons of dry sherry before serving the soup.
Alternatively, cook 2 chopped celery stalks, 1 chopped scallion and 4 tablespoons of melted butter in a saucepan over medium heat. Once the vegetables are softened, add 1 minced clove of garlic. Whisk in 1/3 cup of flour, followed by 2 cups of half-and-half. Let the mixture simmer for five minutes before stirring in 3 1/2 cups of fish stock and 3 tablespoons of chopped parsley.
Cook the soup for 10 minutes or until it starts thickening. Add 8 ounces of cooked shrimp, and simmer the soup for another 10 minutes before serving it. Garnish each bowl with a sprinkle of seafood seasoning or croutons.