In a large pot over medium-high heat, melt butter and add onion, sautéing until softened, about 2-3 minutes. Add garlic and sauté for another minute.
Pour in chicken broth, heavy cream, broccoli, carrot, dry mustard, nutmeg and salt/pepper and bring to a boil. Reduce heat to medium-low and simmer for about 15 to 20 minutes, until the broccoli and carrots are tender.
Mix in cream cheese and cheddar cheese until melted, serve and enjoy!
