Curried Squash Soup

Preheat oven to 375 degrees and bake squash for 30 minutes, until tender. While squash bakes, melt butter in medium saucepan. Add onion, celery, apple, salt, and pepper. Cover and cook 5 minutes over moderately low heat, stirring occasionally.

Add curry powder, broth, and bay leaf. Raise heat and bring mixture to a boil. Reduce heat, cover pan, and simmer for 30 minutes. Discard bay leaf.

When squash is cool enough to handle, discard seeds, peel, and cut it into chunks. In batches in a blender or food processor, purée broth mixture with squash. Return soup to saucepan. Add buttermilk and lemon juice. Adjust seasonings, heat the soup through, but do not boil it.