If you plan to use sweet dumpling pumpkins (or any other medium-sized pumpkins) as serving bowls, you'll need one pumpkin per serving. Cut the tops off and scrap the seeds with a measuring spoon. Skip this step if you don’t plan to use pumpkins as bowls.
Preheat the oven to 200 C or 400 F. Cut the medium-sized sweet dumpling (or small Hokkaido pumpkin), spaghetti squash and butternut squash in halves and scrap out the seeds with a measuring spoon.
Arrange your pumpkin bowls (if using), 1/2 of a spaghetti squash, 1/2 of a butternut squash and a sweet dumpling (or Hokkaido) halves on a baking tray lined with parchment paper. Sprinkle with a little salt and black pepper, drizzle with 1 tablespoon olive oil and roast for about 30 minutes.
Take the butternut squash out of the oven after 20 minutes, let it cool a bit, then peel and chop it.
Heat the remaining tablespoon of olive oil in a medium-large heavy-bottomed pot and sauté finely chopped shallot, minced garlic, chopped sage and butternut squash chunks for a few minutes. Add turmeric, ground paprika and water and bring to a boil. Add the millet, reduce the heat, cover and cook for 12-15 minutes.
Once the other pumpkins are ready, scrape the flesh of the spaghetti squash into strands using a fork. Scrap the sweet dumpling or whatever pumpkin you are using for the puree with a spoon and mash it with a fork. Add to the soup.
Serve the soup in roasted pumpkin bowls (optional). Season with salt and black pepper to taste and garnish with pumpkin oil, fresh sage and pumpkin seeds.