Method:

1. Preheat the oven to 180°C fan force. Line a baking tray with baking paper.
2. Halve the broccoli heads and thin make incisions into the stalk (this will help it cook evenly). Place on the prepared tray with the leek, drizzle with olive oil, and season. Wrap the garlic in foil and place on the tray. Roast for 1 hour or until vegetables are tender.
3. While the vegetables are roasting, place the sourdough and olive oil in a bowl and toss to coat. Top sourdough pieces with cheese, place on a lined baking tray and roast for 15 minutes until crisp. Set aside.
4. Once the vegetables are tender, remove from the oven and transfer to a large saucepan. Squeeze the garlic from their cloves into the pan, then add the stock, baby spinach, 1 cup water and 1 tsp salt. Use a stick blender to blitz everything together, adding a little more water if needed to loosen, then stir through the sour cream. Season with salt and pepper to taste. Serve soup with croutons, extra sour cream, chilli flakes and herbs if desired.