Add garlic to mixer bowl, chop for 3 sec/speed 9/MC on.
Add onion to mixer bowl, chop for 3 sec/speed 5/MC on. Scrape bowl down.
Add butter and cook for 10 min/100°C or 212°F/speed 1/MC off.
Add water, chicken stock and apple to mixer bowl, cook for 15 min/steaming temp/speed 1/MC on.
Remove apple from the broth and discard, put prepared mussels into the deep steaming tray, put it in place and cook for 5-7 min/steaming temp/speed 2 or until mussels are opened.
Set mussels aside, add crème fraîche and parsley to soup, stir for 10 sec/speed 3/MC on. Pour hot soup over mussels and enjoy.