Put all the paste ingredients except the coriander leaves into a liquidiser and whiz until smooth, then scrape into a bowl.
Roughly chop the tomatoes and add to the liquidiser, season well, then blitz until smooth and put aside.
Preheat your oven to 200°C/400°F/gas 6.
In a large casseroletype pan, toss the cauliflower florets and onions with half the curry paste.
Add 600ml (1 pint) of water, and roast for 40 minutes, stirring halfway through.
After 40 minutes, carefully move the hot pan from the oven to the hob.
Drain and add the chickpeas, along with the stock and blitzed tomatoes and simmer on a medium heat for about 30 minutes.
Mash a few times to thicken the sauce.
Add the delicate veggies (corn, peas, beans and spinach) for the last 3 minutes of cooking, then have a taste and correct the seasoning. Marble through a few dollops of yoghurt, scatter over the reserved coriander and chopped fresh chilli (leave the seeds in for extra heat), then take straight to the table.