In a large saucepan, sauté the onion and cooked bacon with the olive oil until onion is golden. Add the mushrooms and cook, stirring for about 10 minutes. Add flour and cook for another minute and stir well. Add the chicken stock, potatoes and apple cider vinegar. Stir well. Simmer for 15 minutes or until the potatoes are tender. Transfer the ingredients from the saucepan into a food processor; puree the soup mixture to a relatively smooth consistency. Return the soup to the saucepan and add the milk; stir well. Gently re-heat the soup and when heated through, ladle the soup into bowls and garnish with the chopped parsley. Makes 6 servings.
