Preheat oven to 400 degrees then trim cauliflower into florets, discarding the stalk. Place cauliflower on a rimmed baking sheet and drizzle with 1 Tbsp of olive oil. Roast cauliflower for 30–35 minutes until tender and golden along the edges.
Place a large saucepan over medium heat. Add remaining 1 Tbsp olive oil and diced onion. Cook 4–5 minutes, stirring often until onion is translucent. Add minced garlic and thyme then cook for 1 additional minute.
Add roasted cauliflower and broth to the pot, reserving a few small florets for garnish if desired. Bring to a boil, stirring constantly and breaking up any large chunks of cauliflower. Reduce heat to low, cover and simmer for 15 minutes.
Carefully ladle about half the soup into a blender and purée until smooth. Work in batches if necessary until entire soup is pureed, but don’t fill the blender more than ⅓ full. Add puréed soup back into the pot and stir in milk. Add shredded cheese a handful at a time, stirring until completely melted before adding more.
Season with salt and pepper to taste and garnish with reserved roasted cauliflower, fresh parsley, bacon and cheese. Enjoy!
