Heat the olive oil in a large nonstick skillet. Add the onions and cook, stirring occasionally, until softened, about 5 minutes. Stir in the garlic and cook for 1 minute.
Transfer the onion mixture to a 6-quart slow cooker. Add the kidney beans, sweet potato, quinoa, diced tomatoes, Italian seasoning, salt and pepper.
Stir in the vegetable broth.
Cook on LOW for 6 to 8 hours or on HIGH for 3 to 4 hours, or until the sweet potato is tender.
Stir in the spinach, parsley and hot sauce. Adjust seasonings to desired taste. Serve.