Root vegetable soup

This soup was inspired by a recipe for white vegetable soup in the Mustards Grill Napa Valley cookbook. My version primarily uses root vegetables, and the result is a creamy soup with a unique flavor. This recipe freezes really well - if you're planning to freeze it, omit the milk/cream and add it to the reheated soup just before serving. You could garnish this soup with bacon, fresh herbs, pesto or croutons.

Root vegetable soup
Serves 4

3 small leeks or 1-2 large leeks, white parts only (use the dark tops to make vegetable stock)
1 small white onion
1 medium parsnip
2 medium turnips
1 one pound celery root
4 cups vegetable or chicken stock
2 teaspoons olive oil
2 tablespoons of milk or cream
salt and pepper

Slice leeks thinly. Peel all of the other vegetables and cut into 1/2 inch chunks. Saute the leeks and onions in the olive oil until softened and onions are translucent. Add the rest of the vegetables and a pinch of salt and pepper - saute for about 5 minutes. Add the stock, bring to a boil. Lower the heat to a simmer and cook until the vegetables are tender, about 20 minutes. Puree the soup in a blender in two batches. Add more salt and pepper to taste, stir in milk or cream.