Spinach Soup

INGREDIENTS
3 cups chopped fresh spinach
1 cup medium chopped onion
2 medium potatoes cut in cubes
1 1/2 Cups water
1/4 cup butter
1 cup Milk
1/2 teaspoon salt
1/8 teaspoon pepper
1/4 cup sour cream
METHOD
1 In a large saucepan or pressure cooker over medium heat, sauté onion in butter for 3 minutes. Add potatoes, water and bring to a boil. Reduce heat to low, cover and simmer for 10 minutes or until the potatoes are medium tender. Add spinach and pressure cook for on medium heat for 3 whistles minutes.
2 Purée soup mixture in a blender. Return to saucepan. Whisk in milk, salt and pepper.
3 Over low heat, bring the soup to simmering. Whisk in the sour cream.
Soup can be served hot. Garnish with a dollop of sour cream.