Cook the pasta according to 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 onion and half teaspoon each salt and pepper and cook, stirring occasionally until soft, 14 to 16 minutes. Transfer to a plate; reserve the skillet.

Add the pumpkin, thyme sprigs , and 1 half cups water to reserved skillet, cover partially, and cook, stirring occasionally, until the pumpkin is very soft and most of the water evaporated, 6 to 8 minutes.

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

Serve the pasta with black pepper and additional pecorino, if desired.

TIP: you can substitute almost any winter squash for the shipper pumpkin. But are not will give you a sweeter pasta, kabocha or acorn a more savoury one