Roasted Root Vegetable Soup

Another great recipe from 'A Cooks Year' by Bridget Jones. Vegetables roasted in olive oil give this winter soup a wonderful depth of flavour. Just use what you have and adapt quantities to suit.
You need;-
1/4 cup/50ml olive oil, 1 small butternut squash - peeled, seeded & cubed, 2 carrots - cut into thick rounds, 1 lge parsnip - cubed, 1 small swede - cubed, 1 x leek - thickly sliced, 1 onion - quartered, 3 bay leaves, 4 thyme sprigs, 3 rosemary sprigs, 1.2 ltrs/5 cups vegetable stock, seasoning, sour cream to serve.
You preheat the oven to 200 degrees c/400 deg f or gas 6. Put olive oil into large bowl, add prepared veg and toss until coated in the oil.
Spread out veg in a single layer on one large or two small baking sheets. Tuck the bay leaves and thyme & rosemary sprigs among the vegetables.
Roast veg for about 50 mins until tender, turning occasionally to make sure they brown evenly. Remove from oven, discard herbs and transfer the veg to a large pan.
Pour stock into the pan and bring to the boil. Reduce the heat, season to taste, then simmer for 10 mins. Puree with a stick blender or use food processor, until thick and smooth.
Heat through. Season and serve with a swirl of sour cream and garnish with sprig of thyme. I served it with hot bread - delicious.