Roughly chop the broccoli florets and place them in the bottom of the crockpot. Add the chopped onion, shredded carrots, cream cheese, and minced garlic.

In a large bowl, whisk the chicken broth with nutmeg, salt, pepper, and cornstarch until smooth. Pour the mixture over the vegetables in the crockpot and stir to combine.

Cover and cook on HIGH for 2-3 hours (or on LOW for 6-7 hours), until the broccoli is tender. For a smoother texture, use an immersion blender to blend the soup, leaving some chunks if preferred.

Reduce the heat to LOW, then add the milk and shredded cheddar cheese. Cook for an additional 30 minutes, or until the cheese has melted completely.