You can buy a mix at the store & add water & an egg. But I got a recipe from my Simple & Delicious magazine (which I highly recommend to anyone, regardless of whether you're dieting or not. Great simple recipes, most sent in by readers.) You get a new issue every 2 months, I think it's like $15 a year.
Here it is:
Egg Drop Soup
From Taste of Home's Simple & Delicious
INGREDIENTS
3 cups chicken broth
1 tablespoon cornstarch
2 tablespoons cold water
1 egg, lightly beaten
1 green onion, sliced
DIRECTIONS
In a large saucepan, bring broth to a boil over medium heat. Combine cornstarch and water until smooth; gradually stir into broth. Bring to a boil; cook and stir for 2 minutes or until thickened.
Reduce heat. Drizzle beaten egg into hot broth, stirring constantly. Remove from the heat; stir in onion. Yield: 4 servings.
1 WW point per serving.
Here's a link to the site. Best magazine subscription I've ever purchased.
http://www.bestsimplerecipes.com/default.aspx