- 2 medium heads cauliflower, separated into large florets
- 1/2 cup plus 6 tablespoons extra-virgin olive oil, divided
- Kosher salt and freshly ground black pepper
- 6 slices bacon
- 1 large white or yellow onion, peeled and finely chopped (about 1 1/2 cups)
- 6 cups homemade or store-bought low-sodium vegetable or chicken stock
- 1/4 cup half and half
- 1/2 cup chopped fresh parsley leaves
Adjust oven racks to middle positions and preheat oven to 400°F. Toss cauliflower with 4 tablespoons olive oil and salt and pepper to taste. Divide between 2 rimmed baking sheets and roast, stirring occasionally, until deeply browned and tender, about 25 minutes. Remove from oven.
Meanwhile, lay bacon slices in a cold cast-iron skillet, then set over medium heat. Cook, flipping once, until browned and crispy, about 6 minutes. Drain bacon on a paper towel, then chop or crumble into bite-sized pieces.
Heat 2 tablespoons olive oil in a large, heavy-bottomed Dutch oven set over medium heat. Add onion and cook, stirring occasionally, until onions are translucent but not browned, about 6 minutes. Add roasted cauliflower and stock, bring to a boil, reduce heat, and simmer for 5 minutes.
Let soup cool slightly, about 10 minutes. Add half and half and use a hand blender to blend soup until smooth. Alternatively, blend soup in a blender in two batches. Season to taste with more salt and pepper. Keep soup warm.
Combine remaining 1/2 cup olive oil and parsley in blender and blend until smooth, about 1 minute. Pass oil through a fine-meshed sieve.
To serve, ladle soup into bowls, garnish with parsley oil, and sprinkle with chopped bacon. Serve immediately.
Blender or hand blender