Saute onions, carrots, and celery in 4 tbsp butter until soft, about 5 min. Add garlic and saute for another minute. Add broccoli and cauliflower. Add spices, salt and pepper. Stir until fragrant, about 1 min. Add the broth and cover. Simmer for 10 min. Add the the milk to the flour and stir to combine. Make sure all of the flour is incorporated into the milk. After the 10 minutes add the milk and cream to the soup. Simmer for another 5 min. After the 5 minutes, remove from the heat and add the cheese. Stir until the cheese has melted. Finish with the parsley. Remove the bay leaf and serve.