Finely chop the onion, celery and garlic.
Heat the oil in a saucepan, then sautée them until soft.
Meanwhile, peel and chop the carrot, sweet potatoes and swede into small chunks. Add these to the pan, together with the oregano and stir for a minute.
Pour in the passata. Use the bottle to add enough water to cover the veggies and add the stock cube or powder.
Bring to the boil and cook for 20 minutes or until the root vegetables are soft. Turn off the heat.
Using a stick blender or liquidiser, purée the soup, until it’s smooth or slightly textured.
Add the fresh herbs and process again for a few seconds.
Serve warm - reheat if necessary.