Cook the vegetables. Add olive oil to a large pot or Dutch oven over medium heat. Add the onion and cook for 3-4 minutes, stirring occasionally. Add the carrots and celery to the onions and continue to cook for an additional 5 minutes. Finally, add the butternut squash, garlic, and apple to the pot, mixing well to combine. Cook over medium heat, stirring often, for 5-7 minutes, or until butternut squash just starts to turn tender.
Add the water. Add the water or vegetable broth to the pot. Increase heat to high and bring to a low boil. Cover and reduce heat to low. Simmer for 5 minutes.
Add the pumpkin puree, spices, and lentils. Stir in the pumpkin puree, spices, and lentils, mixing well to thoroughly combine. Return liquid to a simmer before reducing heat to low and covering with a tight-fitting lid. Simmer for approximately 60 minutes, stirring every 5-10 minutes.
Add Coconut Milk. After 45-60 minutes, stir in the coconut milk and continue to simmer, covered and over low heat, until lentils are tender and fully cooked.
Optional. For a more blended, less chunky, lentil soup, transfer part (or all) of the soup to a large blender and process until smooth. Take extra care and do this step in smaller batches if you are pureeing while the soup is still hot.
Season and serve. Season the soup to taste with additional salt, pepper, and curry seasoning if desired. Garnish each bowl with coconut cream, green onions, and sunflower seeds. Enjoy!