Trim the top of broccoli bunch, about 1 1/2 pounds, to fill one cup. Set aside for garnish. Cut remaining broccoli in two inch pieces. Large stems can be halved or quartered. Place these large broccoli pieces, not the garnish, in saucepan. Add enough water to cover. Cook 5 minutes. Similarly, cook garnish in boiling water for 2 minutes. Drain both and set aside.
Melt 4 tablespoons butter in saucepan. Add 6 tablespoons flour, stirring well. Add 5 cups chicken stock, stirring rapidly. Cook until thickened and smooth. Add large broccoli pieces. Simmer about 10 minutes. Put soup contents into blender; may take 2-3 times. Blend until smooth. Return to pan and bring to a boil. Add salt and pepper to taste. Add garnish, 1/2 cup of cream, 1/2 cup of milk, and 1/4 teaspoon nutmeg. Serve hot. Makes 6-8 servings.