1. In a large pot over high hear, boil the potatos in the chicken broth for 15 min. or until they are tender. Carefully separate potato from the broth and transfer to a blender or a food processor.
2. Add 3/4 cup of broth (sometimes you need to add more that what the recipe calls for depending on how much the potatos absorbed) and puree for 5 seconds or more depending on how smooth you want the soup to be. Add remaining broth and set aside.
3. Melt butter in a large sauce pan over medium heat; add salt, ground black pepper, onion, and dill weed. Stir and saute for 2 min. Sprinkle with flour and stir well.
4. Pour milk in butter mixture and heat until the mixture starts to thicken; about 2 min. Stir in the pureed potato. Allow to heat through and serve.