Heat the oven to 220C (200C fan)/425F/gas 7.
Cut the cauliflower into even-sized florets, leaving small ones whole and halving the larger ones (keep any small leaves intact).
Transfer to a roasting tray, toss with the turmeric and vegetable oil, and season well.
Roast for about 25 minutes, until golden and charred around the edges.
Meanwhile, bring a small pan of water to a boil, then add the eggs.
Boil for seven minutes, then drain and plunge into cold water.
Once cool, peel and cut into quarters.
Put the curry powder in a bowl and mix with two tablespoons of just-boiled water.
When smooth, mix in the mayonnaise, yoghurt and chutney.
Taste and adjust the seasoning.
Cut the lettuce into thin wedges and put them in a large serving bowl with the spring onions and chives.
Toss in the roast cauliflower and dressing, then add the eggs, sprinkle over the nigella seeds and serve.
