This soup is a vegetarian and gluten-free spin on the hearty fall classic. A hot, velvety bowl would serve just as well on the Thanksgiving table, or a cozy winter night in front of the TV.
Preheat oven to 350°F.
Cut squash in half and seed. Place the halves on a baking sheet, cut-side down. Bake until tender when pierced with a knife, 45 minutes to 1 hour. Scoop out esh when cool enough to handle.
Heat oil in a large saucepan over medium. Add celery, onion, and carrot and stir to coat. Cover, reduce heat to medium-low, and cook, stirring frequently, until soft, 8 to 10 minutes. Stir in the squash esh, cumin, chipotle to taste, and cloves. Add broth and simmer, covered, until the vegetables are very tender, 20 to 25 minutes.
Puree the soup with an immersion blender or in a blender (in batches) until smooth. (Use caution when blending hot liquids.) Season with salt and pepper. Garnish with yogurt and chives (or parsley).