In a large stockpot, melt the butter over medium heat.
Add onion, garlic, salt, pepper and nutmeg to the pot. Saute for 5 minutes, stirring frequently, until onions are translucent.
Add in the carrots and stir to heat through, approximately 1 minute.
Stir in the veggie broth and the cauliflower florets. Mix well to combine with sauteed onion/carrot blend.
Cover pot and simmer for 20 minutes, stirring occasionally, until cauliflower is fork-tender.
Remove lid and stir in the heavy cream. Simmer for 5 minutes, stirring occasionally.
Remove from heat. Using an immersion blender, carefully blend until soup is smooth and creamy-- this takes approximately 5 minutes.
Add in a third of the shredded cheese and stir to melt. Repeat with remaining cheese, stirring after each addition to combine until smooth.
Serve as desired and season with more salt/pepper and/or toppings.