3 cups (1-inch) cubed butternut squash (about 1 1/4 pounds)
3 cloves garlic, minced
1 tablespoon olive oil
Kosher salt
Freshly ground black pepper
3/4 cup heavy cream
1/2 cup low-sodium chicken or vegetable broth
1/2 cup grated Parmesan cheese, plus more for serving
Pinch ground nutmeg
1 pound dry fettuccine
2 tablespoons finely chopped fresh parsley
Step 1: Arrange a rack in the middle of the oven and heat to 425°F.
Step 2: Toss the cubed squash with the garlic and olive oil in a large bowl and season with salt and pepper.
Step 3: Transfer the mixture to a rimmed baking sheet and spread into an even layer. Roast until tender and caramelized, about 30 minutes.
Step 4: Remove the squash from the oven and let cool for 10 minutes. Transfer to a blender or food processor.
Step 5: Add the cream, broth, cheese, and nutmeg, and blend until smooth. Season with salt and pepper as needed; set aside
Step 6: Meanwhile, bring a large pot of salted water to a boil. Add the fettuccine and cook until al dente, about 10 minutes or according to package instructions. Reserve 1/2 cup of the pasta water, then drain the pasta.
Step 7: Return the pasta to the pot.
Step 8: Add the Alfredo sauce and toss with the pasta. If needed, add some of the reserved pasta water, tablespoon by tablespoon, to loosen the pasta and evenly coat it with the sauce. Sprinkle with the parsley and more Parmesan and serve immediately.