Pre heat the oven at 395 F = 200 C.
Wash all vegetable and peel the potatoes, parsnip, carrots and onion
Cut veggies into four then dice into big chunks.
Layer the veggies in a large non stick baking tray, add the herbs, drizzle the oil and sprinkle some salt. Mix well using your hands.
Bake in the oven for about 45 minutes or until veggies are roasted. Meanwhile bring a pot of water to a boil
Remove veggies from the oven then remove the sprigs.
Transfer the vegetable into a large pot and cover with the boiling water.
Bring to a boil again then keep on boiling for 10 more minutes.
Turn the heat off and leave to cool for 5-10 minutes.
Use a blender to puree the vegetables in the same pot. Start on low for a couple of minutes then increase to the highest setting until the soup is smooth. Add hot water to get the desired consistency, bit by bit, while continuing to blend.
Serve warm or cold with croutons. Serve with sour cream or/and chopped parsley for added flavor.