1. Fill and boil your kettle. Put a large pan on a medium heat. Add 1 tsp cumin seeds and toast for 1 min till the seeds start to pop and jump. Tip them into a large bowl and set aside. Take the pan off the heat.
2. Peel and finely chop the onion. Put the pan back on a medium heat for 2 mins, then add 1 tbsp oil and the onion. Season with a pinch of salt and fry, stirring often, for 5 mins till the onion starts to soften and become golden.
3. While the onion fries, peel and grate the garlic and ginger. Stir the garlic and ginger into the onion. Cook, stirring often, for another 3-4 mins.
4. While the veg fry, dice the tomatoes. Halve the chilli, scoop out the seeds and white pith and finely chop the chilli (you can leave the seeds and pith in if you prefer a hotter curry). Add the tomatoes and chilli to the pan. Cook, stirring often, for 5 mins till the tomatoes are soft and pulpy.
5. Stir 1 tbsp vegetable curry powder into the pan. Add the lamb and cook, stirring, for 2-3 mins with a wooden spoon to break up any lumps.
6. Pour in 250ml hot water from the kettle, cover, bring to the boil then turn the heat down and simmer for 20 mins. Stir every so often to stop the lamb sticking. The keema should thicken a little while it cooks, and the lamb become tender.
7. While the lamb keema cooks, rinse the rice under cold water and then tip it into a small pan. Pour in 300ml boiling water and add a pinch of salt. Cover, bring to the boil and then reduce the heat and very gently simmer for 8-10 mins till all the water has been absorbed. Take the pan off the heat and leave it in the pan, lid on, to steam for at least 5 mins to finish cooking the rice. The rice will keep warm in the pan for up to 15 mins.
8. While the rice cooks, make the raita. Coarsely grate the cucumber into the bowl with the cumin seeds. Add the yogurt with a pinch of salt and sir well to mix.
9. When the keema has thickened and is tender, stir in the spinach till it wilts. Taste the keema and add a pinch of salt if you think it needs it. Fluff the rice with a fork and spoon onto 2 warm plates. Top with the keema. Serve with the raita.