This is my favorite version of the classic fall squash soup. Kabocha is a Japanese variety of squash, now available at most markets. It is squat and green and delicious. Squash or pumpkin soups tend to work well with an added flavor, like apple or, in this case, fennel. This recipe is adapted from Suzanne Goin’s soup in Sunday Suppers at Lucques. It takes a little time and effort to prepare but in the end, it is well worth it.
Preheat your oven to 400°F. Using a large, sharp chef’s knife, trim the squash stem and root ends, cut the squash in half lengthwise, and remove the seeds. Place the squash
cut side down on a cutting board, remove the peel with a sharp knife or a vegetable peeler. Cut
the squash into 1-inch-thick wedges and cut the fennel
into 1/2-inch-thick wedges. Combine both in a large bowl and toss with 2 tablespoons olive oil, 1 teaspoon salt, and a few grinds of black pepper. Spread in a single layer on a baking sheet and roast in oven for 30 minutes, or until tender and slightly caramelized.
While the vegetables roast, toast the fennel seeds (if using) in a small pan over medium heat for 2 minutes, or until aromatic. Grind in mortar and pestle or spice grinder.
Heat a heavy-bottomed soup pot over medium heat for 1-2 minutes. Add the remaining olive oil, onions, fennel seeds, thyme, chili flakes, bay leaf, remaining 1 teaspoon salt, and a few grinds of black pepper. Cook, stirring frequently, for about 10 minutes, or until the onions are soft. Add the roasted squash and fennel, stir to combine, and add the sherry or apple cider vinegar, if using. Let the liquid boil away and cook down for a couple minutes. Add the stock, bring to a boil, then reduce to a simmer, and continue to cook for about 20 minutes.
Due to the large volume of this recipe, this soup needs to be pureed in 2-3 batches. Strain the soup through a colander set over a large bowl or another pot. Purée the soup in a blender in batches by combing one-third of the solids with 1 cup of the broth. Purée on low speed at first (BE SURE the pour lid is removed; hot liquid makes stream, which will cause a potentially dangerous blender eruption if the pour lid is sealed intact), increasing to high speed while also adding a little liquid at a time until the soup has a silky consistency. It may take a couple minutes to purée per batch and you may not use all of the broth. Repeat the purée process as needed. Taste the finished soup and season with additional salt to taste as needed. Garnish with sour cream and candied pumpkin seeds if desired.