Heat the oven to 200°C/180°/400°F. Chop the cauliflower into florets. Cut the courgette lengthways into four strips, cut each strip into three pieces.
Spread the vegetables out in a roasting tray, sprinkle over the nigella seeds, turmeric and salt and drizzle with the olive oil. Toss everything together to coat then roast for 25-30 minutes until the vegetables are tender and lightly browned.
Meanwhile, to make the yellow rice, heat the olive oil in a saucepan over a low heat and add the chopped onion. Cook for about 5 minutes until softened.
Add the crushed garlic, turmeric and yellow mustard seeds and cook for another minute. Add the rice and stir to coat then add the water and vegetable stock cube.
Bring up to a simmer, pop a lid on the pan and cook over a low heat for 10 minutes. Switch off the heat and leave to steam for 10 minutes; don’t open the pan until the 10 minutes is up!
While the rice is cooking make the salsa. Finely chop the tomatoes and coriander and thinly slice the spring onion. Place them in a bowl with the lime juice and zest and a generous pinch of salt. Stir it all together.
Once the rice is ready, stir in the rasins and half the pistachios. Season to taste with salt and pepper.
Serve the rice topped with the roasted vegetables, the salsa and a scattering of pistachios.