Roast the Garlic:

1. Preheat your oven to 400°F (200°C).
2. Cut the top off the garlic bulb to expose the cloves. Drizzle with olive oil, wrap in aluminum foil, and roast for 30-35 minutes until soft and caramelized.
3. Allow to cool slightly, then squeeze out the roasted garlic cloves and set aside.

Sauté the Vegetables:

1. Heat olive oil in a large pot over medium heat.
2. Add the diced onion and sauté for about 5 minutes, or until translucent.

Cook the Cauliflower:

1. Add the chopped cauliflower florets to the pot and cook for another 5 minutes, stirring occasionally.

Add Broth and Garlic:

1. Pour in the vegetable broth and add the roasted garlic cloves.
2. Bring the mixture to a boil, then reduce the heat and simmer for 15-20 minutes, or until the cauliflower is tender.

Blend the Soup:

1. Use an immersion blender to purée the soup directly in the pot until smooth.
2. If using a countertop blender, carefully transfer the soup in batches and blend until smooth, then return it to the pot.

Add Cheese and Milk:

1. Reduce the heat to low and stir in the milk (or cream).
2. Gradually add the shredded cheddar cheese, stirring until it’s fully melted and the soup is creamy.
3. Season with salt and pepper to taste.

Serve:

1. Ladle the soup into bowls. Garnish with fresh chives or parsley if desired.
2. Enjoy with crusty bread or crackers for dipping!