Adapted from Bon Appetit (February 2011 issue)
3 TBSP butter
3 cups chopped leeks (about 3 large leeks; white and pale green parts only)
6 teaspoons chopped fresh thyme
1 1/4 cup chopped broccoli
4 cups chicken broth
1/2 cup half and half
Melt butter in a large pot. Add leeks and 4 tablespoons of thyme. saute until leeks are almost soft, about 7-8 minutes.
Transfer 1/4 cup leeks to a small bowl and set aside.
Add broccoli and chicken broth. Bring to a boil. Cover and boil for 8-10 minutes.
Puree the soup in a blender, adding the half and half.
Season with salt and pepper.
Ladle into bowls and top with reserved leeks and remaining thyme.