How To make Sweet Potato Soup with Buttered Pecans

***FOR THE SOUP*** 3/4 cup finely chopped onion
1 cup finely chopped leek

washed well and
:

drained 2 large garlic cloves

minced
3 large carrots :

sliced thin
1 bay leaf
3 tablespoons unsalted butter
2 pounds sweet potatoes
1 russet baking potato
5 cups chicken broth

plus additional for
:

thinning the soup, -- if desired 3/4 cup dry white wine
1 1/2 cups water
***FOR THE BUTTERED PECANS*** 3/4 cup chopped pecans
2 tablespoons unsalted butter
creme fra