Curried Zucchini 'N Potato Soup

I am a soup lover. Many of my friends find this hard to believe as they all think that I only eat ,drink and dream of desserts. I came up with  this recipe today and believe me, it was real good. We enjoyed this soup to the last drop. Friends, do give this a try and I am sure you will love this simple soup in this cold weather. 
Ingredients:
1 tablespoons extra virgin olive oil
1tablespoon butter
1 large onion, halved and thinly sliced
1 tablespoon curry powder
salt to taste
2 small zucchini, halved lengthwise and cut into 1 inch slices
2 potatoes cooked and cubed
4 cups chicken stock/vegetable stock
1tablespoon allpurpose flour
Method:
Heat the oil and butter in a large pot. Saute the onion, and season with curry powder and salt. Saute until onions are translucent. Add  zucchini, and cook until tender. Stir in the flour. Pour in the chicken stock. Bring to a boil. Cover, reduce heat to low, and  simmer 10 minutes. Remove soup from heat. Use a hand blender, or transfer in batches to a blender, and blend until almost smooth. Add the cubed potatoes and simmer for another 10 mintues.