This velvety soup pairs the gentle flavor of sauteed leeks with sweet, roasted squash. Topped with a dollop of sour cream and a few caramelized apple croutons, it embodies everything cozy about autumn.
Preheat the oven to 350 degrees. Place the squash, cut side down, on a baking sheet and bake until tender, about 40 minutes. Let cool slightly and gently scrape or cut squash away from skin (delicata skin is edible, but not tasty in this dish). Set aside.
Melt butter in saucepan over low heat. Add leeks and thyme and stir occasionally until soft and brown, 10-15 minutes. Stir in the stock and the squash and simmer over medium heat for 20 minutes. Using an immersion hand blender, puree the soup directly in the pot until smooth. (Alternatively, puree the soup in batches in a standard blender or food processor).
Season with salt and pepper & top with sour cream and caramelized apple croutons
To make the croutons:
Peel and core apple and halve lengthwise. Using a mandoline or a very sharp knife, cut apple into very thin slices. Line a baking sheet with parchment paper and spread one layer of apple slices on top. Sprinkle with brown sugar. Bake slices for 20 minutes at 350 degrees until crisp.
Transfer to cooling racks and let cool completely.