Steam the cauliflower florets until tender.

Microwave or boil potatoes until soft.

In a large pot, combine the steamed cauliflower, potatoes, chicken broth, and milk.

Bring to a boil, then reduce heat and simmer for 10 minutes.

Carefully puree the mixture using a blender or immersion blender.

Return the pureed soup to the pot and stir in half of the chives, sour cream, salt, and pepper.

Simmer for another 5-10 minutes, stirring occasionally.

Serve hot, garnished with shredded cheese, remaining chives, and crispy bacon.