Creamy chicken and mushroom soup with rocket pesto

1. Bring the chicken stock to simmering point in a medium–sized saucepan. Add the chicken and simmer gently for 8 minutes, then remove the pan from the heat and leave the chicken to cool in the stock for 15 minutes. Remove the chicken with a slotted spoon and, when cool enough to handle, shred the meat into pieces and discard the bones. Spoon out 2 tablespoons of the stock into a cup or bowl and set aside, reserving the rest of the stock in the pan.
2. Place a large heavy-based stockpot over a low–medium heat. Add the margarine, leek, potato and sage and cook, with the lid on but slightly askew, for 8–10 minutes, stirring regularly, until the vegetables are soft. Add the mushrooms and cook for a further 3–4 minutes. Add the stock from the saucepan, season with salt and pepper to taste and cook for 10 minutes until the potato is tender. Allow to cool for a few minutes, then blend with a hand-held blender until smooth. Return to a low–medium heat, add the milk and shredded chicken and bring to simmering point.
3. For the rocket pesto, blend baby rocket, olive oil, lemon juice and garlic together, along with the 2 tablespoons reserved stock, then season with salt and pepper to taste.
4. To serve, ladle the hot soup into bowls and garnish with pesto.

TIP: Add diced carrot or celery or some fresh thyme or parsley to the soup base for a different flavour.