Cream of Spinach

Cream of spinach is a very tasty French soup. It doesn't take very long to prepare. Here's the recipe:

450 grams spinach
1 onion
2 potatoes
2 tablespoons butter
4 cups chicken or vegetable broth
2/3 cup cream
salt
pepper

Peel and chop the onion.
Peel and dice the potatoes.
Melt the butter in a pot over medium heat.
Add the onions and cook until soft.
Add the diced potatoes and broth.
Bring to a boil and then reduce to a simmer.
Cook for 20 minutes or until the potatoes are tender.
Add the spinach and cook for 5 more minutes.
Use a blender to puree the soup and then return to the pot.
Stir in the cream and add the salt and pepper.
Heat and serve.