Preheat the oven to 425°F. Line a rimmed baking sheet with parchment paper.

Using a large chef's knife, cut the round part of the butternut squash from the long part. Slice the round part in half and scoop out the seeds. Slice the long part in half as well, lengthwise. Brush or spray the parchment lightly with vegetable oil and place the squash pieces, cut side down, on the baking sheet. Roast for about 45 minutes, or until the squash is very tender. At this point, you can let the squash cool and refrigerate to use the following day, or proceed with the recipe.

Preheat a 4-quart pot over medium heat and add the oil. Sauté the onion in the oil with a pinch of salt for about 7 minutes, until lightly caramelized. Add the garlic and ginger and sauté until fragrant, about 30 seconds.

Mix in the red pepper flakes and the remaining ½ teaspoon salt. Add the white wine and deglaze the pan by scraping the bottom with a wooden spatula. Peel the roasted squash and add it to the pan along with the broth. If a little of the butternut skin gets in, no big deal. Add the coconut milk, maple syrup, and lime juice and heat everything through.

Use an immersion blender to blend the soup until smooth and creamy. If you don't have an immersion blender and need to use a food processor or blender, remember that steam can build up in there and hurt you. So lift the lid every few seconds to let steam escape. Thin with a little water if necessary, taste for seasoning, and serve. If you like, swirl a little coconut milk into the top of each serving for extra prettiness. Sprinkle with a pinch of red pepper flakes and chopped scallions.