Finely dice the bacon and vegetables. In a deep saucepan over medium heat fry the onion and bacon in the butter and oil for a few minutes. Add the cauliflower and garlic and fry for a few minutes more.
Add carrot, capsicum, celery, potato, water, stock cubes and pepper to taste. Simmer gently for 30 minutes.
Add the milk and blend the soup to a smooth consistency.