Caramelized Leek Soup

Directions

1. 1
   Halve leeks lengthwise and thinly slice crosswise.
2. 2
   In a large bowl of cold water wash leeks well and lift from water into a large sieve to drain.
3. 3
   In a 6-quart heavy kettle cook leeks in butter over moderately low heat, stirring occasionally, until some begin to turn golden, about 40 minutes.
4. 4
   Stir in sugar and cook, stirring occasionally, 10 minutes.
5. 5
   Stir in vermouth and cook, stirring occasionally, until liquid is evaporated and most leeks are golden, 10 to 15 minutes.
6. 6
   Deglaze kettle with 1/2 cup broth and cook, stirring occasionally, 10 minutes more, until liquid is evaporated and leeks are deep golden.
7. 7
   Add remaining 3 cups broth and bring soup just to a boil.
8. 8
   Season soup with salt and pepper.
9. 9
   Serve soup, garnished with chives, with cheese toasts.