Prep and Sauté: Slice the onion and mince the garlic. Wash the mushrooms thoroughly, pat them dry, and slice them to ⅛ inch thickness. Preheat the pan to medium-low heat. First, cook the onion in butter for 3 minutes. Then, cook the garlic for 1 minute with olive oil.
Mushrooms: Preheat the pot on medium-low heat. Add the mushrooms and cook for 2 minutes without adding the spices. When the mushrooms release their liquid, add the following spices: nutmeg, paprika, salt, ground white pepper, and apple cider vinegar to the pot. Stir to mix and cook the mushrooms for another 2 minutes.
Simmer and blend soup: Add the garlic and onion to the pot. Add the chicken stock cube, bay leaves, and 3 cups of water, and bring the soup to a boil. Then, lower the temperature and simmer for 15 minutes with the lid closed. Remove the bay leaves and blend the soup with an immersion blender. Ensure the soup has cooled down if the mixer container is not glass.
Cook with cream: After blending the soup, add the heavy cream and cook for 2 minutes on medium-low heat, stirring occasionally. Garnish with finely chopped parsley and slices of cooked mushrooms.