Sweet potato, carrot and coriander soup

1 sweet potato - quite large, chopped into chunks

6 to 8 carrots - chopped into chunks

1 large onion, sliced

Knob of butter

2 vegetable stock cubes

2 pints of water

Large bunch of coriander

Saute the onion in the butter and cook until transparent.  Add the sweet potato and carrot, stock cubes, water and coriander.  Simmer until all the vegetables are cooked - about 40 minutes.  Process in a blender until smooth and check seasoning.  You can add a little cream when serving or crumble some Stilton cheese on the top and enjoy with crusty warm bread.

If you don't add any cream, this will freeze brilliantly :)