Preheat your oven to 200°C/Fan 180°C/Gas 6. Peel and roughly chop the onion and tumble into a roasting tin. Pull any tatty leaves off the cauliflower and save the rest. Chop the cauliflower into small chunks and tumble into the tin. Add the cauliflower leaves too.

Drizzle over 1 tbsp olive oil and 1 tbsp garam masala. Drop on the whole, unpeeled garlic cloves. Add a good pinch of salt and pepper then toss everything together. Slide into the oven to roast for 30 mins.

While the cauliflower roasts, finely grate the turmeric (no need to peel, but see our tip on stain-free prep). Halve the chilli and flick out the seeds. Finely chop the chilli. Trim the roots and any ragged greens from the spring onions then thinly slice them.

Fill and boil the kettle when the cauliflower has roasted for 25 mins. Remove the tin from the oven. The cauliflower should be softened and lightly caramelised at the edges. Lift out the garlic cloves and roasted cauliflower leaves and set to one side.

Place the roasting tin on a medium heat on the hob (alternatively transfer the roasted veg to a large pan). Pour in 750ml hot water from the kettle and add the grated turmeric. Bring up to a bubble then simmer for 5 mins. While the soup is simmering, squeeze the roasted garlic cloves from their papery skins and add to the soup.

Drop in most of the cashews, saving a few for garnish. Add most of the chilli. Using a hand-held blender, blitz the soup till smooth and creamy. Taste and add more salt or pepper if you think it needs it. Ladle into warmed bowls and top with the crispy cauliflower leaves, sliced spring onion, remaining chilli and the cashews to serve.