Wash and dry the sugar pumpkin. If the pumpkin is too tall to fit in the Instant Pot, cut the stem using a chef's knife by laying the pumpkin sideways on a damp kitchen towel, so it stays stable.
Pour 1 cup water in the inner pot of a 6 qt Instant Pot, or 2 cups for an 8 qt. Place the trivet and put the pumpkin on the trivet. Close the lid. Set the valve to Sealing mode. Press Manual, high, for 12 minutes. (check time variation in recipe notes)
Let the pressure release naturally. Open the lid after the pin drops, remove the pumpkin and let it cool for 10 minutes. Slice the pumpkin in half or quarters. Using a spoon, remove the seeds and stringy core. You can save the seeds for roasting, if you wish.
Using a sharp spoon, scoop out the flesh, like you would for an avocado. The skin is so soft that it starts separating very easily from the flesh. Blend the pumpkin flesh in a food processor or blender until smooth. Use water as needed, a tablespoon at a time.
Oven Roasted Pumpkin Puree (for 2 or more pumpkins)
Preheat the oven to 350°F. Wash and dry the sugar pumpkin.
Cut the stem using a chef's knife by laying the pumpkin sideways on a damp kitchen towel, so it stays stable. Now slice it in half. Using a spoon or an ice cream scoop, remove the seeds and stringy core. You can save the seeds for roasting, if you wish.
Line a baking tray with parchment paper or foil. Place the pumpkin face down on the sheet (flat side down). Roast in the oven for 40-45 minutes, or till the pumpkin skin darkens and the flesh is fork tender. The exact time will depend on the size of the pumpkin.
Cool the pumpkin for 10 minutes. Using a large spoon, scoop out the flesh, like you would for an avocado. Blend the pumpkin flesh in a blender or food processor until smooth. Add water as needed to reach your preferred consistency.
Notes
Look for sugar or pie pumpkin. They are smaller, sweeter and pop up in supermarkets around September. These are not the same as the pumpkins you get from pumpkin picking.
For medium size pumpkins (3-4 pounds), adjust the Instant Pot cooking time to 15 minutes, high pressure. Let the pressure naturally release. The pumpkin flesh should be fork tender. If it's still hard, cook for 5 minutes more at High pressure, with another natural release. Let it cool for 10 minutes, then finish slicing, deseeding and pureeing.
If the pumpkin is too big to safely fit in your Instant Pot, remove the stem, cut in half and scoop out the seeds and strings. Cut into quarters and place on the trivet. Cook on high pressure for 5 minutes, followed by a natural pressure release.
Don't fret about the seeds and strings. Scooping out the seeds and stringy core will take a little muscle power, but it's okay if some strings remain. This will not affect the taste or texture of your puree.
No oil is necessary. We want pure pumpkin puree without any addition flavor. This really makes the pumpkin shine.
Puree in a blender, food processor or with a potato masher. I found I got the best results with the blender, but use whatever pureeing tool you have on hand. A potato ricer or food mill can also work.
Add water, if necessary. The moisture content in each little pumpkin will vary. If your pumpkin is dry or not blending, add 1 Tablespoon of water at a time until a smooth consistency is reached. That being said, if you find your pumpkin puree to be too watery, strain through a fine mesh sieve to rid of extra moisture.
Use immediately or store for later. Feel free to make pumpkin bread or any of your favorite pumpkin recipes as soon as the puree is ready. It will also keep for up to one week stored in an airtight container in the fridge. Just make sure to bring to room temperature before using.
Freeze to enjoy pumpkin any time of year. Simply place about 1 cup portion sizes (the equivalent of ½ can) into small Ziplock freezer bags, push out all the air and seal tight. Label, date and freeze flat in your freezer for up to 3 months. When ready to use, thaw to room temperature right on your kitchen counter or overnight in the fridge.
Note: The nutrition facts below are my estimates. If you are following any diet plan, I recommend cross-checking with your preferred nutrition calculator.