1Caramelise the onion in the deep pan on the oil. Cook it on low for about 8-10 mins.
2Add the parsnip, leek, celery and bay leafs. Let it sweat for 6-8 mins covered. Stir occasionally.
3Add the vegetable stock and bring to the boil and simmer covered for about 10 mins. Stir occasionally.
4Remove the bay leafs and discard.
5Add the apple and cook for another 2 mins.
6Take off the heat and blend it till the soup is smooth.
7Season to taste.