Start by preheating your oven to 400°F. While it's heating, line a large baking sheet with parchment paper or lightly wipe it with olive oil. Using parchment prevents sticking without extra fat, which is perfect for monitoring browning. Now for the squash: cut it lengthwise (like a hot dog, not like a baseball). This orientation matters because it creates a flat surface that makes direct contact with the hot pan, maximizing the Maillard reaction. Scoop out all seeds and stringy bits with a sturdy spoon—you want a clean cavity. Place both halves cut-side down on your prepared pan. This positioning is critical: the cut surface will caramelize against the pan, creating deeper color and flavor. If you place them cut-side up, the flesh steams instead of roasts.

Slide the pan into your preheated oven. You're looking for the squash to develop a golden-brown color on the exposed rounded skin—this takes about 30 minutes. You'll know it's ready when you can pierce the flesh easily with a fork and the skin has deepened in color. The cut side won't brown during this phase because it's facing down, and that's exactly what you want. We'll flip things in the next step.

Remove the pan carefully (use mitts—it's hot). The squash doesn't need flipping. Instead, arrange your prepped vegetables around the squash: the diced onion, halved jalapeños, minced shallot, and unpeeled garlic cloves. Drizzle everything (squash, all vegetables) with about 2 tablespoons of olive oil and season with fleur de sel and cracked pepper. This second phase roasts for another 30 minutes. The garlic will release its aroma when it's done—you'll smell it intensely around the 25-minute mark. The onions should caramelize at the edges, and the jalapeños should wrinkle slightly. When you press a garlic clove, it should yield immediately.

Remove the pan and let it rest for 10-15 minutes. This resting period is crucial: it allows carryover cooking to finish (the squash continues cooking from residual heat) and, more importantly, it cools things enough to handle safely. Once cool, scoop the squash flesh from its skin using a sturdy spoon—it should come away cleanly in large pieces. Discard the skin. Squeeze the garlic cloves from their papery skins directly into a large pot (they'll pop right out). Add the squash flesh, roasted onion, jalapeños, and shallot to the pot.

Pour in your 2 cups of vegetable broth and the full can of coconut milk (don't drain or separate—use the whole can). Add the 4 sage leaves, torn by hand. Sprinkle in ¼ teaspoon of ground nutmeg and the ½ teaspoon of apple cider vinegar. Don't add salt yet—we'll adjust at the end.

This is where your technique matters enormously. Use an immersion blender (my preferred tool for this) or a standard blender. If using an immersion blender, submerge the head fully before turning it on—never blend with the head above liquid, as it splashes and oxidizes the soup unnecessarily. Blend for about 2-3 minutes on high speed. The soup should transform from chunky to completely smooth. You're not just mixing; you're physically breaking down cell walls and creating the stable emulsion we discussed earlier. If using a standard blender, work in batches and never fill more than ⅔ full (hot soup expands). Blend each batch for about 60 seconds, then pour into a clean pot.

Once blended, return all soup to your pot (if batched). Bring it to a gentle boil over medium-high heat—you'll see large bubbles breaking at the surface. Once boiling, reduce heat to low and simmer for 20-30 minutes. This gentle simmering achieves two things: it infuses the sage flavor throughout and it allows the soup to reduce slightly, concentrating flavors naturally without any added stock or reduction. You should notice the aroma becoming more aromatic and complex around the 15-minute mark. After simmering, taste carefully (it's hot). Add fleur de sel and cracked pepper to your preference. Taste again after 2 minutes—salt needs time to distribute fully. If the soup tastes flat or overly sweet, add another ¼ teaspoon of apple cider vinegar. The acid will make the sweetness recede and bring all flavors into focus.