Preheat an oven. Place cubed butternut squash, onion, and halved garlic cloves on a large rimmed baking sheet. Drizzle with olive oil, Kosher salt, and black pepper. Place the fresh sage leaves and thyme sprigs on top. Roast.
Discard the fresh herbs, then place roasted vegetables in a large soup pot along with vegetable or chicken broth. Squeeze as much of the roasted garlic in as you like. The rest can be saved and spread on toast or added to sautéed veggies!
Place the soup over medium heat, stir in ground nutmeg, then bring to a simmer and warm through. Taste, adjust seasoning as needed, adding additional Kosher salt and black pepper to taste. While the soup is simmering, cook the pancetta.
Heat remaining olive oil in a skillet over medium heat. Add cubed pancetta, then cook, stirring occasionally, until the fat has rendered and the pancetta is crispy on all sides. Do not let it burn.
When ready, divide the roasted butternut squash soup into individual bowls. Drizzle with either heavy cream or extra virgin olive oil. Add a few crispy pancetta cubes on top, then garnish. Enjoy immediately!