In a large pot, melt the butter over medium heat. Add the onion, carrots, and garlic. Saute for 4 - 5 minutes until carrots start to soften.
Add the cream,beer, mustard, nutmeg, salt and white pepper to the pot. Bring to a boil and reduce heat to low. Simmer for 7 minutes.
In a small bowl, combine the broth and cornstarch. Stir until all the lumps are gone. Add to simmering pot and stir to combine. Bring to a simmer for another 2 minutes until soup has thickened.
Add the cheese slowly, stirring continually.
Serve with popcorn for garnish.