Step 1: Prepare the Butternut Squash

1. Preheat the oven to 400°F (200°C). Line a baking sheet with parchment paper.
2. Toss the diced butternut squash with 1 tablespoon of olive oil, salt, and pepper.
3. Spread the squash evenly on the baking sheet and roast for 25-30 minutes, or until the squash is tender and slightly caramelized.

Step 2: Make the Parmesan Crisp

1. While the squash roasts, preheat a non-stick skillet over medium heat.
2. Spoon 1-2 tablespoons of grated Parmesan cheese onto the skillet, forming a small mound. Flatten it gently with the back of a spoon.
3. Cook for 2-3 minutes until the cheese melts and turns golden brown.
4. Carefully remove the crisps with a spatula and set them aside on a plate lined with paper towels.

Step 3: Start the Risotto Base

1. Heat 1 tablespoon of olive oil in a large pan over medium heat.
2. Add the chopped onion and cook for 3-4 minutes until translucent.
3. Add the minced garlic and cook for another minute until fragrant.
4. Stir in the Arborio rice, coating it with the oil and allowing it to toast for about 2 minutes. The rice should become slightly translucent around the edges.

Step 4: Deglaze with White Wine

1. Pour in the white wine and stir continuously until it has mostly evaporated, about 2 minutes.

Step 5: Add the Broth

1. Begin adding the warm broth, one ladle at a time, stirring frequently.
2. Allow each ladle of broth to be absorbed before adding the next. This process should take about 18-20 minutes.
3. Continue adding broth and stirring until the rice is creamy and tender with a slight bite (al dente).

Step 6: Incorporate the Butternut Squash

1. Once the rice is cooked, add the roasted butternut squash, butter, and chopped sage leaves.
2. Stir well to combine. The squash should break down slightly, adding to the creaminess of the risotto.
3. Add grated Parmesan cheese and heavy cream (if using) for extra richness.

Step 7: Season and Serve

1. Season the risotto with salt, black pepper, and nutmeg.
2. Serve the risotto immediately, topped with a Parmesan crisp for a delightful crunch.