Preheat your oven to 400°F (200°C). Prepare a baking sheet by lining it with aluminum foil. Place the cauliflower florets and trimmed garlic bulb onto the sheet. Drizzle with olive oil and sprinkle with salt and pepper. Wrap the garlic securely in foil. Roast in the preheated oven for about 25-30 minutes until the cauliflower becomes tender and starts to brown.

Once the cauliflower and garlic are roasted, allow them to cool slightly. Then, remove the garlic cloves from their skins. Add the roasted cauliflower and garlic to a blender. Pour in the chicken broth and blend until the soup is smooth and creamy. If you prefer a chunky texture, blend less.

Transfer the blended soup into a saucepan. Add the heavy cream, stirring to combine. Heat over medium heat, bringing to a simmer. Taste and adjust the seasoning with salt and pepper. Stir occasionally to prevent sticking and to ensure the soup is evenly heated through.

Ladle the soup into bowls and garnish with freshly chopped parsley. Serve it hot alongside keto-friendly bread or on its own to appreciate its rich, roasted flavors.