Preparing the Pumpkin: Preheat the oven to 355°F (180°C).
Wash the Hokkaido pumpkin to remove any dirt. Cut the pumpkin in half or quarters with a sharp knife. Remove the seeds and any stringy bits with a spoon.
Roasting the Pumpkin: Place the cut pumpkin pieces on a baking tray and use parchment paper or aluminum foil for easier cleanup. Roast it with the skin on.
Optionally, sprinkle a light dusting of salt over the pumpkin to enhance its natural sweetness.
Bake in a preheated oven for 45 to 55 minutes or until the flesh is soft enough for a fork to slide through easily.
Making the Puree: Once the pumpkin is roasted, let it cool. Then, peel away the skin if you prefer, though it's edible and packed with nutrients.
Transfer the pumpkin flesh (and the skin, if desired) to a blender or food processor. Blend until smooth. If the puree is too thick, add a few teaspoons of water until you reach your desired consistency. Note: Hokkaido pumpkin contains less liquid compared to other pumpkin varieties. Food processor purees faster without adding more water. Once cooled, store in a tight-lid jar, zip lock bag or container, then refrigerate or freeze.