Just made this tasty soup from:
about 1 muesli bowl full of mashed potato
1 bunch of kale
3 portobello mushrooms
about 800 ml of vegetable stock
Fry shallots in a bit of butter or oil. Add washed (and stringed, if your blender is as crap as mine) kale. After a few minutes, add diced mushrooms.
Add vegetable stock once mushrooms have shrunk a bit, just so that everything is covered.
Cook for a bit, so that the stock takes on the taste of the vegetables.
Optional: add a bit of smoked paprika and/or ground nutmeg. You can also serve the soup with a bit of (whipped) cream and roasted nuts.