Heat your oven to 425°F and toss the cubed butternut squash with olive oil, salt, and pepper on a large baking sheet. Roast for 20–22 minutes until the edges turn golden and a fork pierces the flesh easily—this concentrates the natural sweetness and eliminates excess moisture that would dilute your final soup.

While the squash roasts, melt butter in a large pot over medium heat and sauté the diced onion until translucent, about 4–5 minutes. Add the minced garlic and cook for another 60 seconds until fragrant, stirring constantly to prevent burning.

Pour the vegetable broth into the pot with the aromatic base and bring to a gentle simmer. This butternut squash soup base should bubble lightly but never aggressively—aggressive heat can cause splattering and reduces the creamy texture later.

Once the butternut squash finishes roasting, carefully add it to the simmering broth along with the sage, thyme, and nutmeg. Simmer for 5 minutes to allow the flavors to meld before blending.

Using an immersion blender, purée the mixture until completely smooth, working in batches if your pot is small. For an extra-velvety texture, strain through a fine mesh after blending.

Reduce heat to low and stir in the heavy cream, tasting as you go and adjusting salt and pepper to your preference. Never boil after adding cream—this prevents curdling and maintains that luxurious mouthfeel.

Ladle into bowls and garnish with toasted pumpkin seeds, a drizzle of cream, or crispy sage leaves for restaurant-style presentation.