1. Heat oven to 200C/180C fan/gas 6.
2. Put the carrots and sliced onions, oil, garlic and thyme in a roasting tin. Season and toss everything together.
3. Place in the oven and roast for 25 minutes, or until tender and beginning to turn golden.
4. Remove 3 tablespoons of caramelised onions retaining for the garnish.
5. When the carrots and onions are golden remove from the oven and transfer to a deep saucepan.
6. Squeeze the soft roasted garlic cloves out of their skins and pop in the saucepan. Add the thyme discarding any woody thyme stalks.
7. Bring to the boil, then simmer for 10 minutes.
8. Liquidize, taste and season to taste.
9. Return to the saucepan and reheat when ready to serve.
To serve the stylish way: Garnish with sprigs of thyme and the reserved onions.