Peel and dice the vegetables (cut swede smaller as takes longer to cook), keeping the onion separate.
Add the stock, salt and pepper.
Bring to the boil and simmer with the lid on for about 25 - 30 minutes or until the vegetables are tender (push a piece of swede against the edge of the pan with a wooden spoon and if it breaks in half easily you're good to go).
Blend (don't over blend or soup will turn gloopy).
Taste, and adust seasoning if necessary.
Reheat and serve with crusty bread.
Instead of grating the ginger you can use an electric mini chopper which will make light work of this job!