Heat a large Dutch oven over medium heat. Melt the coconut oil then sauté the onions and sliced apples for 3-4 minutes, or until soft and lightly brown. While the apples and leeks cook, mince the ginger then stir into the pot. Stir well to incorporate. Add the chopped squash along with the coconut milk and 16 ounces of water or stock. Cover, bring to a boil, then lower the heat and simmer for 20 minutes. Using an immersion blender or upright blender, puree until smooth and creamy. Add sea salt, to taste.