Dilled Zucchini Soup for All Seasons

A lot of zucchini coming out of the garden right now and I'm thinking of all sorts of ways to prepare it.  Cooler nights this week so soup was in order.  I took one of those zucchini and added potatoes, dill and chicken broth and made this soup.  The next day I tasted the leftovers chilled and it was just as good!  Truly a soup for all seasons!!

Makes about 2 quarts

2 Tbl butter
2 Tbl extra virgin olive oil
1 medium onion, diced
4 medium red skin potatoes, peeled and cubed (about 4 cups) or more:see note below
1 medium zucchini grated on the large holes of a box grater (about 3 cups)
1 tsp salt
1/2 tsp black pepper
3 Tbl minced fresh dill or 1 Tbl dried
6 cups chicken broth
1/2 cup sour cream
Thinly sliced green onion for garnish(optional) if serving warm
Finely diced cucumber for garnish (optional) if serving chilled

In a 4 quart soup pot, melt the butter along with the olive oil, add the diced onion and saute until the onion softens bu doesn't brown.
Add the diced potatoes, shredded zucchini, salt, pepper and dill and continue to saute while stirring for 3 or 4 more minutes.
Add the chicken broth, bring up to a boil and then simmer for about 20 minutes until the potatoes are fork tender.
Cool the soup a bit and then puree with an immersion blender or blend in batches in a regular blender.  To serve warm, bring the soup just barely to a boil and whisk in the sour cream.  garnish each bowl with green onion if desired.  To serve cold, after whisking in the sour cream, cool the soup to room temperature and then chill in the fridge for several hours (or overnight) before serving and garnish with cucumber.
NOTE:  For a thicker soup add a few more potatoes to the mix.