100g chopped veg (e.g. soup mix of carrot, swede, turnip, leek, cauliflower; or for oriental style use a stri-fry selection like red pepper, mange tout, baby corn, bamboo shoots, beansprouts, mushroom)
1 tsp bouillon powder (Marigold is my preference) or stock cube.
Bring to boil and simmer 10 minutes.
Stick blender is the really easy way to get this to a nice chunky texture, really worth having one for making soups (unless you get one of the soup makers).
For an oriental style soup, I add half a tsp of red thai curry paste along with the bouillon powder, and pour in some light coconut milk before serving.
This is so easy that we have it often on a fast day, before our main course.
You will find this and other soup recipes in my new book, 5:2 Healthy Eating for Life, which you can preview or download a sample of on Amazon (that includes all the soups I think!).