1 cauliflower, head chopped into small florets and leaves saved (see Tips below)
4 large garlic cloves, crushed
1 tbsp grated fresh root ginger (or ginger purée)
500g/1lb 2oz new potatoes, larger ones halved or quartered
500g/1lb 2oz tomatoes, chopped (or 400g tin chopped tomatoes)
salt and freshly ground black pepper
2 tsp cumin seeds
4 tsp mild curry powder
2 tsp nigella seeds (optional)
1 tbsp tomato purée
2 tsp turmeric
3 tbsp butter or ghee
plain yoghurt
freshly cooked rice or warmed naan bread