Chop the onion and cut the garlic cloves into small pieces.
Heat olive oil in a large saucepan (it should be a little higher, this is helpful when pureeing) and sweat onions and garlic in it. Add rosemary sprigs and fry briefly. Peel the sweet potatoes and cut into small pieces, add to the saucepan and fry briefly.
Pour the chicken or vegetable stock on top, bring to the boil, cover and simmer for about 15-20 minutes. The cooking time depends on the size of the sweet potato pieces, which should be pleasantly soft - just give it a try.
Remove the rosemary sprigs and puree the soup with a blender. Pour the cream on top and let it boil down for a few minutes. Season with orange juice, salt, pepper and, if you like, chilli.
Tip: If the peel of the orange is suitable for consumption, rub off some zest before pressing and serve the soup garnished with a dollop of whipped cream, orange zest and possibly a sprig of fresh rosemary.