Buttery Pappardelle With Mushrooms

• ¾ pound pappardelle
• 6 tablespoons unsalted butter
• 1 large sweet onion, thinly sliced
• 8 ounces crimini mushrooms, sliced
• Sea salt and black pepper
• ½ small sugar pumpkin (about 1½ pounds)—peeled, seeded, and cut into ½-inch pieces [may substitute butternut, acorn, or hubbard squash]
• 3 thyme sprigs, plus 2 teaspoons thyme leaves
• 2½ ounces parmesan, grated (⅔ cup)

Cook the pasta according to the package directions. Reserve 1 cup of the cooking water; drain the pasta and return it to the pot.

Meanwhile, melt 2 tablespoons of the butter in a large skillet over medium heat. Add the onion and ½ teaspoon each salt and pepper and cook, stirring occasionally, five minutes. Melt 2 tablespoons of butter in the skillet. Add the mushrooms and 1 tsp thyme leaves and cook until mushrooms are slightly browned and onions are soft, about 12 more minutes. Transfer to a plate; reserve the skillet.

Add the pumpkin, thyme sprigs, and 2 tablespoons butter to the reserved skillet, cover partially, and cook, stirring occasionally, until the pumpkin is browned and very soft, 6 to 8 minutes.

Add the onion, mushrooms, pumpkin, thyme leaves, pecorino, the remaining 2 tablespoons of butter, and ½ cup of the reserved cooking water to the pasta and toss to coat (adding more cooking water as needed to loosen the sauce).