Cauliflower Soup

I have adapted this recipe from a segment I saw on the Today Show

2 tablespoons olive oil
1 tablespoon butter
2 medium leeks
1 shallot
1 head cauliflower
4 cups chicken broth
2 bay leaves
salt
pepper
1/4 teaspoon curry powder

1. Dice leeks, shallot and coarsely chop cauliflower.
2. Heat oil and butter in large pot (I use my Le Crueset). Add leeks and shallot, saute until soft. Add salt, pepper and curry saute 1 minute. Add cauliflower, saute for 3 minutes.
3. Add chicken broth and bay leaves. Simmer about 15 minutes.
4. Remove bay leaves and puree using immersion blender.