Heat large pot on medium heat. Add bacon and cook till crispy, about 8 minutes. Place on paper towel lined plate and set aside.
In the same pot, melt butter and add garlic, onions, carrots and celery. Stir until onions are clear.
Add cauliflower and bay leaf. Cook and stir occasionally until tender.
Whisk in flour for about 1 minute, or until browned. Add chicken broth and milk gradually while whisking constantly until it thickens.
Bring to a boil then reduce to simmer until cauliflower is tender, about 12-15 minutes. Add salt and pepper to taste. If consistency is too thick, add more broth or milk until desired.
Serve piping hot and garnish with chunks of bacon and parsley.