Sweat onion and garlic in 1 olive oil until soft. Increase heat, add squash, cauliflower and pepper flakes. Saute for 5 minutes. Stir in broth and water, bring to a boil and simmer for about 10 minutes until squash is very soft.
Puree soup with an immersion blender or in batches in your blender per manufactures directions for hot liquids. Add bell pepper, cream, sweetener, and simmer about 5 minutes or until peppers are tender. Stir in spinach and sausage, simmer until heated through, about 2 minutes. Season with salt and black pepper.
Instant Pot Instructions
Using the saute feature saute onions and garlic in oil, add squash and pepper flakes, saute for about 5 min. Add broth and water.
Place lid on IP and use the soup button, process until squash is soft. Allow pressure to release naturally and remove lid from IP.
Puree squash mixture with an immersion blender and add bell pepper and sausage heat through, stir in cream and spinach and allow spinach to wilt.
Notes
You can also use turkey sausage or shredded chicken breast for a lighter version.