1/2 cup chopped onion
2 cups cauliflower
1/2 tsp butter or olive oil
salt and pepper
2 cups vegetable broth
1 large bag pre-washed spinach or arugula
Heat a soup pot to medium and mist with olive oil cooking spray. Add onion and cook until soft, about 4 minutes, Add butter, then cauliflower and season with salt and pepper. Cook until cauliflower is just starting to brown, then pour in broth. Cover, bring to a boil, reduce heat and cook 15-20 minutes.
Stir in arugula and once it has wilted (it will take just a minute) pour soup into blender. Puree until smooth and serve topped with a sprinkle of Parmesan cheese.