Place a large baking sheet in the center rack of the oven. Preheat the oven to 425 degrees F.

In a large bowl, toss the cauliflower and radishes with the oil, ½ teaspoon salt and ¼ teaspoon pepper. Carefully remove the hot baking sheet from the oven and spread the vegetables on the baking sheet in a single layer. Roast until the vegetables are tender and caramelized in spots, stirring once or twice, 25 to 30 minutes.

Place the bacon in a large saucepan over medium-low heat. Cook, stirring occasionally, until the bacon is crisp and golden, 10 to 13 minutes. Using a slotted spoon, transfer the bacon to a small dish. Pour off all but 1 tablespoon bacon fat. Add the onion and celery to the pan, sprinkle with ¼ teaspoon salt and cook, stirring, until tender, about 5 minutes. Add the garlic and saute until fragrant, about 1 minute. Pour in the broth, add the roasted vegetables and bring to a boil. Reduce the heat, partially cover and simmer to allow the flavors to meld, about 20 minutes.

Working in batches, transfer the soup to a blender. Add the butter and ¾ cup cheese and blend, being careful of hot liquid, until smooth. Season with salt, pepper and hot sauce if desired. Return the soup to the pan to rewarm if needed.

Kcals: 330, Total Fat: 24 g, Sat Fat: 12 g, Cholesterol: 60 mg, Sodium: 1230 mg, Carbs: 14 g, Fiber: 4 g, Protein: 22 g, Sugar: 5 g