Sure, you can buy canned pumpkin, but it's cheaper, healthier, and tastier to make your own pumpkin purée. All you need is a nice pumpkin (smaller is better), a few common kitchen tools, and some time.
Marinade is one of the most flexible recipes there is, because there is no set recipe: just combine a few liquids with herbs and spices, you don't even really need to measure.
Miso soup, or "miso shiru," is a typical Japanese soup that comes in many varieties. This one is spiced up with pumpkin, onion, and optional curry powder.