Preheat the oven to 200°C (400°F).

Cut the butternut squash in half crosswise to separate the neck from the round, seeded part.

Take the seedless neck part first. Cut it in half lengthwise, then slice each half into three thick half-moons, about 4 cm (1.5 inches) thick. You will get 6 half-moons in total. Don’t cut them too thin or they’ll turn mushy.

For the seeded part, cut it lengthwise in half and scoop out the seeds with a spoon. Take one half and cut it lengthwise in half again, then cut each of those pieces crosswise in half. Repeat with the other half, so you’ll have about eight thick pieces in total.

Finally, peel all the slices with a vegetable peeler.

Sprinkle the sugar evenly over the slices. Using a spoon or your hands, make sure every piece is well coated in sugar.

Wet a piece of parchment paper, squeeze out the excess water, and cover the baking dish with it. Bake on the middle rack for 30 minutes.

Remove the paper, flip the pumpkin slices gently with a spoon, and bake uncovered for another 15 minutes.

Take the dish out of the oven and let the pumpkin cool completely in the same dish.

Once cooled, transfer the slices to a serving plate. Spoon some of the syrup that has collected in the baking dish over them. Sprinkle with walnuts, drizzle with tahini, and serve. You can also top with clotted cream or Turkish kaymak if you like.