Gingered Carrot Soup

I've made this soup several times, and find that there are no alterations required. Big thanks to Maxine Bonneau for creating such a lovely, smooth, sunny recipe for an easy, quick carrot soup.

2 Tbsps (1oz/28gr) butter
2 onions (12oz), peeled and chopped
6 cups chicken broth (subs. veg broth for vegetarian)
1 lb 8oz carrots, sliced
2 Tbsps grated fresh ginger
1 cup heavy cream
2 tsps salt
¼ tsp pepper

1. In a soup pot, add butter and onions and cook, stirring often, until onions start to soften. 
2. Add the broth, carrots, and ginger. Cover and bring to a boil, then simmer until the carrots are well on to tender.
3. In a blender or with an immersion blender, puree until smooth. (When I'm super picky, I like to first blenderize, then run through a strainer.)
4. Return to the pot and stir in the cream. Add the salt and pepper and reheat until quite hot. The heat will counterbalance the dollop of sour cream added as the finishing touch.