Heat the oven to 400°F with a rack in the middle. Line an uncoated stainless-steel rimmed sheet with parchment.
Spread the 2-inch squash chunks in one layer. Pour the melted tablespoon of ghee or coconut oil over them and toss to coat. Roast for about 30 minutes, until the squash is soft when pierced with a knife.
Meanwhile, melt the separate 2 tablespoons butter, ghee, or coconut oil in a Le Creuset Artichaut enameled pot over low heat. Add the carrot coins and chopped leek. Stir to coat, cover, and let them sweat for 30 minutes without browning.
Remove the lid. Stir in the thyme and 1 1/2 teaspoons mineral salt. Add the 3 cups Meat Stock and the roasted squash. Bring the mixture to a gentle simmer.
Blend until completely smooth with an immersion blender, or carefully blend in batches in a standing blender and return the soup to the pot.
Stir in exactly 1 cup of the finished homemade coconut milk. Taste and add more mineral salt only if needed. For a thinner soup, add filtered water gradually, up to about 1/2 cup. Serve warm.