Curried Butternut Squash Soup

2 lbs frozen butternut squash
1 T butter
2 c chopped peeled Granny Smith apples
(¾ lb)1 ½ cups finely chopped onion
½ cup thinly sliced celery
1 bay leaf
2 tsp curry powder
1 garlic clove, minced
3 (14.5 ounce) cans chicken broth
1/8 tsp salt
½ cup brown sugar (optional, unless you're me in which case it's not really optional.)

Melt butter in a large pot over medium-high heat.  Add apple, onion, celery and bay leaf.  Sautee for 10 minutes.  Stir in curry powder and garlic.  Cook 1 minute more stirring constantly.  Add broth, salt, and squash (and brown sugar, if you want it a little sweeter).
Reduce heat to medium-low and simmer, uncovered, for 20-30 minutes.  Discard bay leaf.  Either mash mixture for more lumpy soup, or puree for smooth soup.