Creamy Asparagus Soup

From babycenter.com

1 tablespoon olive oil
1 teaspoon butter
1 leek or small onion, finely chopped
1 pound fresh asparagus, ends trimmed and cut into 2-inch pieces
4 cups reduced-sodium vegetable or chicken broth
Salt and pepper
About 1/3 cup heavy cream (make my own, see below)
4 to 6 tablespoons sour cream, optional

Heat the oil and butter in a large soup pot over low heat. Add the leek and cook for 6 minutes, stirring frequently. Add the asparagus and cook 1 minute. Raise the heat to high, add the broth, and bring to a boil. Reduce the heat to low, cover, and let simmer for about 15 to 20 minutes, or until the asparagus stems are just tender but not limp and overcooked. Remove from the heat and puree the soup in a blender or food processor. Taste for seasoning and add salt and pepper as needed. Reheat the soup and add the heavy cream. Serve hot. If using sour cream, simply add a dollop to the top of each bowl of soup. (Makes 4 to 6 servings)

Home-made heavy cream:
3/4 c milk
1/3 c butter

Melt butter. Pour into the milk and stir. Use in place of 1 c heavy cream. Note: if using 2% or lower fat content milk, add a tablespoon of flour to thicken.