Spiced Puy lentil and portobello mushroom soup

This may look like a bit of a grey old murky soup but it's full of flavour. We tend to be put off foods that are grey (unless they are silver like the mullet!) but flavour does of course come into it.

1 onion, peeled, halved and roughly chopped
2 cloves of garlic, peeled and crushed
A couple of good knobs of butter
4 large flat mushrooms, thinly sliced
80g Puy lentils, soaked for one hour in cold water
1.5ltrs vegetable stock
2-3tsp English mustard
Salt and freshly ground black pepper

To serve

2tbsp crème fraiche
1tbsp finely chopped chives
Spanish pimento to dust

Heat the butter in a thick-bottomed saucepan and gently cook the onion and garlic for 2-3 minutes until soft, add the mushrooms, cover with a lid and continue cooking, stirring every so often. Add the lentils, stock and mustard, season and simmer gently for about 30 minutes or until the lentils are soft. Blend the soup in a liquidiser until smooth and strain through a sieve if you wish, or leave unstrained.

To serve, mix the crème fraiche and chives together, ladle the soup into warmed bowls, spoon the crème fraiche on top and dust with the pimento.