1. Preheat the oven to 400°F (200°C).
2. Chop the cauliflower into florets and place them on a baking sheet.
3. Cut the top off a garlic bulb, drizzle with olive oil, and wrap in foil.
4. Roast the cauliflower and garlic for 25-30 minutes until golden and tender.
5. In a large pot, heat some olive oil over medium heat.
6. Add chopped onions, celery, and carrots; sauté until softened.
7. Pour in vegetable or chicken broth and bring to a simmer.
8. Add the roasted cauliflower and squeeze in the roasted garlic.
9. Season with thyme, rosemary, salt, and pepper to taste.
10. Simmer for 10-15 minutes to meld flavors.
11. Use an immersion blender or transfer to a blender to puree until smooth.
12. Stir in shredded cheddar cheese until melted and well combined.
13. Adjust the consistency with extra broth if needed.
14. Taste and adjust seasoning if necessary.
15. Serve hot, garnished with extra cheese, fresh herbs, or croutons.
16. Enjoy with crusty bread or a fresh salad on the side.
17. Store leftovers in the fridge for a few days or freeze for later.