Preheat oven to 375F, and spray a large baking sheet with a light coat of spray cooking oil. Cut top 1-inch (2.5 cm) off of the squash, then scoop all of the seeds out of it, cleaning them off and spreading them out on a paper towel to dry slightly.
Cut the top part of the squash into 3 "pie wedges", then those into very thin slices with a mandoline or sharp knife. Lay the pieces over the baking sheet, leaving room in the center for the seeds. Once seeds are also in a single layer, spray everything with cooking oil. Then, shake curry seasoning, onion powder, and 1/4 teaspoon salt over the squash/seeds.
Place sheet in the oven for 20 minutes, (meanwhile work on soup), after 20 minutes, remove seeds and set them aside to cool, then flip all squash pieces and roast them for 20 more minutes, or until they start to brown. Once done, place on cooling rack.
For the soup, peel the remainder of the squash (just the easy-to-get parts), and chop it. In a large pot, warm the sunflower oil over medium heat. Once hot, add squash, onion, and sweet potato to the pot, sauteing for 7 minutes.
Add apple, garlic, ginger, turmeric, cinnamon, and cayenne to the pot, sauteing mixture for 3 minutes, then add in vegetable broth, cover with lid, and bring to a boil. Once boiling, adjust heat to medium-low and simmer for 15 minutes, or until veggies are fork-tender.
Puree the soup ingredients either with an immersion blender, or carefully in batches, in a blender. Once completely smooth, stir in coconut milk, using as much or as little as preferred. Season soup with lemon juice and remaining salt, to taste and serve while hot, topped with seeds and squash chips. Or let it cool to room temperature and store with FoodSaver for later!