Someone posted this in the forum tonight. It was good.
2-4 servings

1lb mushrooms
1 onion
oil
1 pt vegetable stock (veg stock cubes are fine)
2-3oz blue cheese or a dash of cream

Fry the onion and mushrooms in oil or butter. Add stock, water and cheese, then blitz it, add seasoning if required, and serve.

Full recipe counts for blue cheese version:

carbs 26g
protein 28g
fat 35g
fiber 7g
calories: 495