Pasta with Creamy Delicata Squash Sauce and Toasted Hazelnuts

• One small-medium delicata squash, peeled and cut into 1 in pieces (or other variety - pumpkin, butternut, etc.)
• 8-10 oz. fresh whole wheat fettuccine
• 1 tablespoons butter
• 1/2 medium onion red onion, finely diced
• 1 garlic clove, minced
• 1.5 teaspoons minced fresh sage
• Kosher salt and freshly ground pepper
• 1/4 cup mascarpone cheese
• 2 Tbsp.freshly grated Parmigiano-Reggiano cheese, plus more for serving
• 1/4 cup hazelnuts, toasted and roughly chopped
• 2 Tbsp. snipped chives
• freshly grated nutmeg (optional)
• (optional: sauteed beet greens or other leafy green)

Preheat the oven to 425°. Toss squash with a little salt, pepper and EVOO, and spread out on a baking tray. Roast for about 30 minutes, or until tender. Let cool.

In a large pot of boiling salted water, cook the pasta until al dente. Drain the pasta, reserving 1 cup of the cooking water.

Meanwhile, in a medium saucepan, melt the butter. Add the onion, garlic and sage and cook over moderately low heat until the onion is softened, about 7 minutes.

In a food processor, puree the squash - adding a little water as needed - to form a consistent puree. Add the onion mixture and process until smooth. Season with salt and pepper.

Wipe out the pasta pot. Scrape the squash puree into the pot and cook over moderately low heat until hot. Mix in the mascarpone and the grated cheese. Add the pasta (and leafy greens, if using) and the reserved cooking water and toss to coat thoroughly and heat through. Season with salt and pepper. Transfer the pasta to bowls, sprinkle the hazelnuts and chives on top and grate with a little nutmeg and serve right away, passing additional Parmigiano at the table.