Melt butter in a soup pot. Sauté onions for a few minutes and then add mushrooms. Cook for 8-10 minutes on medium heat stirring occasionally.
Add dill, thyme, paprika, garlic and lemon juice. Cook for 2 minutes.
Add broth and soy sauce. Simmer on low to medium heat for a few minutes. In a bowl whisk milk with the flour, removing lumps. Add to the soup while stirring to avoid curdling. Simmer soup to desired thickness. Do not boil the soup, just simmer it.
Add crème fraîche or yougurt and stir.
Garnish with parsley.
Serve with warm crusty bread and a glass of wine .