Heat olive oil in stock pot. Add onion and garlic and saute until tender, about 5 minutes.

Add remaining and bring to a boil. Reduce heat and simmer 10 minutes. Puree with an immersion blender, a food processor, or blender.

Return to stock pot and simmer until thickened, about 5 minutes. Serve with sour cream, cheese, avocado, or raw diced onions if desired.