- 1 small butternut squash (about 2 1/2 pounds), split lengthwise, seeds removed
- 1/2 cup extra virgin olive oil
- Kosher salt and freshly ground black pepper
- 2 thyme sprigs
- 2 cloves garlic
- 1 medium onion, finely sliced (about 1 1/2 cups)
- 1 1/2 quarts fresh carrot juice (see note)
- 1/4 cup chopped parsley (optional)
- 1/4 cup toasted pumpkin or squash seeds (optional)
- Adjust oven rack to middle position and preheat oven to 375°F. Coat squash halves with 2 tablespoons extra virgin olive oil and season with salt and pepper. Place on a rimmed baking sheet lined with aluminum foil with cut side facing up. Place garlic clove and thyme sprig in each seed hollow. Roast until completely tender and lightly browned in spots, about 1-hour total. Remove from oven and allow to cool slightly. Discard thyme and carefully scrape flesh away from skin. Discard skin.
- Meanwhile, heat 2 more tablespoons olive oil in a large Dutch oven over medium-high heat until shimmering. Add onion and cook, stirring frequently, until completely tender and lightly browned, about 15 minutes total. Add cooked squash flesh along with garlic cloves. Stir to combine. Add carrot juice and just enough water to submerge everything. Bring to a boil then remove from heat.
- Transfer soup to a blender (if necessary, work in two batches). Start blender and slowly increase speed to high. With blender running, slowly drizzle in remaining olive oil. Continue blending until completely smooth and creamy. Season to taste with salt and pepper.
- Reheat soup until simmering and serve immediately, garnishing with additional extra-virgin olive oil, chopped parsley, toasted pumpin or squash seeds, and toasted croutons drizzled with extra-virgin olive oil.