¼ cup Oil
1 cup Onion
2 Celery Stalks, about 2 cups
3.5 cups Water
2 tsp Salt
¼ tsp Black Pepper
To prepare the Cauliflower: Remove the leaves, and rinse under cold water. Cut Cauliflower in ½ and cut small florets off one half, and set aside. Cut the remaining cauliflower into medium chunks and set aside.
For the Soup:
Heat the oil in a medium pot, over high heat. Add the onions and saute for 1 -2 minutes. Add Celery, medium chunk Cauliflower, Water, Salt and Pepper. Bring soup to a boil, then reduce heat to low and simmer soup covered for 40 minutes or until cauliflower is soft.
Remove the pot from the heat and puree the soup with an immersion blender, or allow soup to cool if using a standard blender (see note), and puree for 2 minutes or until soup is very smooth. Add Cauliflower florets, return the pot to low heat and simmer until florets are soft, about 10 minutes or longer depending on your taste.
Serve immediately topped with chopped spinach.
Note: be very careful – hot liquids will splash out of a standard blender