Cooking : Butternut Squash Soup II

Ingredients
2 tablespoons butter
1 small onion, chopped
1 stalk celery, chopped
1 medium carrot, chopped
2 medium potatoes, cubed
1 medium butternut squash - peeled, seeded, and cubed
1 (32 fluid ounce) container chicken stock
salt and freshly ground black pepper to taste

Directions
Melt the butter in a large pot, and cook the onion, celery, carrot, potatoes, and squash 5 minutes, or until lightly browned. Pour in enough of the chicken stock to cover vegetables. Bring to a boil. Reduce heat to low, cover pot, and simmer 40 minutes, or until all vegetables are tender.
Transfer the soup to a blender, and blend until smooth. Return to pot, and mix in any remaining stock to attain desired consistency. Season with salt and pepper.