Making your own raita
You can buy tubs of ready-made raita, the cooling yogurt-based condiment served with Indian food, from supermarkets. Or, to make your own, simply mix half a finely chopped cucumber and half a small finely chopped red onion with 200g/8oz natural yogurt, then stir in 1 tbsp chopped mint, a little salt and a squeeze of lemon juice to taste.
Preheat the oven to 220C/gas 7/fan 200C. Pour the oil into a large roasting tin or ovenproof dish and put in the oven for a couple of minutes to heat through. Add all the vegetables to the tin, except the beans, stirring to coat them in the hot oil. Season with salt and pepper and return to the oven for 15 minutes until beginning to brown.
While the vegetables are roasting, stir together the stock, curry paste, chilli, saffron and mustard seeds.
Mix the rice and green beans with the vegetables in the tin, then pour over the stock mixture. Lower the oven to 190C/gas 5/fan 190C. Cover the dish tightly with foil and bake for 30 minutes until the rice is tender and the liquid has been absorbed. Stir in the lemon juice and check the seasoning, then scatter over the coriander and cashew nuts. Serve with a pile of poppadums and a bowl of raita.