Preheat the oven to 200 °C / 400 °F and line a baking sheet with parchment paper.

Rinse and dry the pumpkin dry. Cut the pumpkin from stem to end, and don’t try to cut through the stem, since it’s too tough to cut.

Wiggle a heavy knife to cut through the pumpkin. Then pull each part away. Take your time when cutting the pumpkin. You will probably not be able to cut the pumpkin to the bottom in once.

When the knife gets stuck, wiggle it and remove it, then continue. Do all this while rotating the pumpkin. When you have cut through both sides of the pumpkin, you can pull the halves apart. You should be able to easily separate the stem.

Scoop out the seeds and most of the stringy bits. Then place the halves cut-side-down onto the lined baking sheet.

Roast in the oven until the pumpkin can easily be pierced with a knife and the flesh is soft enough to pull away from the skin. This should take about 45 to 50 minutes at 200 °C / 400 °F.

Let the pumpkin cool. Then scoop the soft flesh out of the halves into a bowl. Use an immersion blender to puree the soft flesh until very smooth.

You could also use a food processor. Place the soft flesh in the food processor and process until very smooth. If you are making a big batch of pumpkin puree, you might need to puree the soft flesh in several batches.