Peel, wash and slice sweet potatoes and carrots. Peel and chop the onion. Heat 2 tablespoons of oil in a pot, fry the onions until transparent. Add carrots and ##potatoes##, fry, dust with sugar, fry briefly.
Season with salt and pepper. Deglaze with broth, bring to the boil, cover and cook for about 25 minutes. In the meantime cut ham lengthwise in half. Heat 1 tablespoon of oil in a frying pan, fry ham slices 1/2-1 minute on each side.
Remove from the pan. Remove the soup from the hotplate, puree it with a blender and pass it through a fine sieve. Stir in crème fraiche. Season again with salt, ##pepper## and nutmeg.
Pour soup into bowls and garnish with ##basil##. Add ham chips.