In a large stock pot, heat oil over medium heat. Add garlic, onion, carrots, celery, and red pepper; saute until vegetables are tender (about 4-5 minutes). Add in cauliflower and cook until cauliflower is tender (about 4-5 minutes).
Stir in flour until it starts to lightly brown (about 1 minute), then whisk in chicken broth, milk, and Greek yogurt. Stir constantly until mixture starts to thicken (about 4 minutes). Add in salt, pepper, garlic powder, and crumbled bacon.
Bring soup to a boil, then reduce heat and let simmer until the cauliflower is soft (about 15 minutes). Ladle into the bowls and top with fresh parsley and cheese (if desired).
Recipe by Tone and Tighten at https://tone-and-tighten.com/creamy-cauliflower-chowder.html