1.In a heavy pot sauté onions and mushrooms in butter over medium heat until onions are soft and translucent, about 15 minutes.
2.Add thyme, paprika, chicken broth, soy sauce and white wine. Bring to a simmer and cook until the liquid reduces by half about 15 minutes.
3.In a small bowl, whisk flour into milk until smooth. Add the milk mixture to the soup and cook until the soup begins to thicken, about 10 more minutes.
4.Over low heat, slowly stir in the sour cream, and lemon juice until both are completely combined. Garnish the soup with parsley and serve hot.