Preheat the oven to 375 degrees F (190 degrees C). Line a baking sheet with parchment paper or a silicone baking mat.
Cut the pumpkin or squash in half from the stem to the bottom. Scoop out and discard the seeds and membranes. Bake for an hour or until tender. To speed cooking time, you can cut the halves into wedges and arrange the pumpkin in a single layer on the lined baking sheet. Cook for about 40 minutes or until tender.
Scoop out the flesh (discard the skin) and transfer it to a large soup pot. Add water, onion, miso, ginger, curry paste, optional chili, and turmeric.
Cook over medium heat, stirring occasionally, for 30 minutes. Transfer to a blender and process until smooth. Pour back into the soup pot.
Put the non-dairy milk and cashews in the blender and process until smooth and creamy. If your blender is not high-powered soak cashews for a couple of hours, drain, and then blend. Pour the cashew cream into the soup and stir to combine. Cook over medium heat until warmed through, 2–3 minutes. Season with salt and pepper to taste. Decorate with herbs, pumpkin seeds, and dried colored peppers if you like. You can also reserve a little cashew cream and swirl it into the soup. Serve hot.
