Cook the onion, garlic and celery until the onion turns translucent. Now add the veggies, bouillion powders (cubes or veggie broth) and enough water to cover the vegetables.

Bring the soup to a boil after which you'll let it simmer until the cauliflower is soft. Keep stirring the pot every now and then to prevent the veggies from sticking to the bottom. Now blend the soup with a stick blender until you've got a smooth consistency. Serve topped with some non dairy cream, croutons, chili, basil or whatever else your heart desires.