In a large pot heat oil over medium heat. Once hot, add the onions and turn the heat down slightly. Saute onions for 5-6 minutes or until softened. Add celery and continue to cook for a few minutes. Add the garlic and cook just for a minute.

Add the cauliflower, potatoes and stock. The stock may not cover the vegetables. Stir and bring to a boil. Turn the soup down to a simmer and place a lid over top and cook for 15-20 minutes until everything is very tender when poked with a fork.

Remove the soup from the heat and cool slightly if you need to transfer it to a blender in stages until completely smooth. If not, use an immersion blender and blend the soup until as smooth as possible. The soup will be quite thick, add water or stock as desired.

Serve while hot with your favorite baked potato toppings.