Melt the butter in a large pot over medium heat. Saute the onions and salt in the butter for 8 minutes. Add the mushrooms and saute for 10 more minutes. Stir in the dill, paprika, lemon pepper,soy sauce and broth. Reduce heat to low, cover, and simmer for 15 minutes.
In a separate small bowl, whisk the milk, wine, and flour together. Pour this into the soup and stir well to blend. Cover and simmer for 15 more minutes, stirring occasionally.
Finally, stir in the parsley and sour cream. Mix together and allow to heat through over low heat, about 3 minutes. Do not boil. Serve immediately.