Pureed Broccoli Soup

Either chicken or vegetable stock can be used in this recipe. Canned broths may be used, f desired. Add enough water to one 14.5-ounce can to make the necessary two cups. If you intend to serve any of these soups cold, use oil; unlike butter, it will not congeal when chilled.
 
2 tablespoons unsalted butter, extra-virgin olive oil, or vegetable oil
1 medium onion, 3 medium shallots, or 1 medium leek (white and light green parts only), chopped
2 tablespoons dry sherry or white wine
2 pounds broccoli (stems peeled and everything chopped)
2 cups chicken or vegetable stock
1 teaspoon salt
Ground white pepper
1 cup whole milk
2  teaspoons minced fresh basil
 
Heat butter or oil in large saucepan over medium-high heat. Add onion; saute until golden, about 5 minutes. Add sherry and broccoli; stir-cook until sherry evaporates, about 30 seconds.
Add stock, salt, pepper to taste, and nutmeg to saucepan; bring to boil. Reduce heat to simmer; cover and cook until broccoli is tender, about 20 minutes.
Ladle broccoli mixture into blender. Add 1 cup milk; blend until very smooth. Return soup to saucepan; cook over low heat until warmed through. If soup is too thick, stir in additional milk to thin consistency. Adjust seasonings. (Soup can be refrigerated for 3 days and reheated just before serving.)
Ladle soup into individual bowls. Garnish with minced basil and serve immediately.