Peel and cube squash, place in a bowl, and coat with olive oil, salt, and pepper. Cover a cookie sheet with foil or parchment paper. (You may need two cookie sheets) Place cubed squash on the cookie sheet and roast in oven 425* for 40 minutes. While squash is cooking, move to the next step.
Heat butter, ghee, or olive oil in a large stockpot, at medium to low heat. Add the garlic, onion, salt, and spices. Sauté until the onion is soft and the spices are fragrant. If the mixture begins to stick to the pan, add 1/2 cup of water. Use your judgment on how much liquid to add.
Next, add mushrooms, (if you are using them) to the stockpot. Cover, and cook for 10 minutes medium to low heat. Add in 3 cups of water or vegetable stock.
Put cooked squash in blender or Vitamix with 1 cup of water or stock and puree until smooth. Puree the squash in batches, so you don't clog up your blender or Vitamix.
Begin to add the squash puree to your stockpot already cooking on the stove. Heat everything together very gently at a low to medium heat. Taste to adjust the seasoning. You may want more cayenne or salt, and pepper.
If you like a sweeter soup, add 1 cup of Orange Juice. I tend to omit the OJ, as I like a more savory soup.
Add fresh lemon juice to individual bowls just before serving.
Topped with yogurt, sour cream, chopped toasted almonds to taste, or pumpkin seeds.