Baked Butternut Squash Ziti

Preheat the oven to 375°F.

Heat the olive oil in a large skillet over medium-high heat (use a skillet with a lid—you’ll need it in a bit). Add the onion and cook for 3 to 4 minutes, until softened. Add the garlic and cook for about 30 seconds, until fragrant. Add the butternut squash, rosemary and nutmeg and season with salt and pepper. Mix to combine.

Add the vegetable broth, then reduce the heat to medium-low and cover the pan. Cook for 15 to 20 minutes, until the squash is very tender.

Remove from the heat and, using a potato masher or fork, mash the squash mixture until smooth. Transfer to a large bowl and stir in 1 cup of mozzarella, 1 cup of Parmesan, the Fontina and the ricotta cheese.

Bring a large pot of salted water to a boil. Add the pasta and cook for about 6 minutes, until almost al dente. Drain the pasta and add it into the squash mixture.

Meanwhile, heat the butter in a medium saucepan over medium heat. Add the flour and cook for 2 minutes. Slowly add the milk, whisking constantly until smooth. Cook for 4 to 6 minutes, stirring constantly, until the mixture thickens enough to coat the back of a wooden spoon. Stir in the mustard and season with a dash of salt and pepper. Add the sauce into the pasta and squash mixture and toss to combine.

Pour the mixture into a 13 by 9-inch baking dish. Sprinkle the remaining ½ cup of mozzarella and ½ cup of Parmesan cheese over the top. Cover the dish loosely with aluminum foil and bake for 45 minutes. Remove the foil and bake for another 15 to 20 minutes, until golden brown and bubbly. Remove from the oven and let it rest for 10 minutes before serving.