- Boil the potatoes: Cook the potatoes for 8-10 minutes or until just tender. Drain.
- Cook the spinach: While the potatoes are boiling, cook the spinach in a steamer over the potatoes for 3-4 minutes, or pierce the bag of spinach several times and cook in the microwave for 2-3 minutes or until wilted. Tip into a colander and drain, squeezing out most of the excess liquid by pressing with the back of a spoon.
- Fry the onion and spices: Heat a large frying pan or wok with 3 tbsp oil. Add the onion and cook over a medium heat for 2 minutes, then stir in the ginger, chilli, ground coriander and turmeric. Cook for a few seconds, then add the potato cubes and stir-fry for 3-4 minutes. Separate the spinach leaves with two forks, then stir into the spicy potato mixture together with the lentils. Season to taste with salt. Heat gently until piping hot.
- Complete the dish: While the potato mixture is warming through, heat the remaining oil in a small frying pan. Add the garlic shreds and cumin seeds, then cook for 1-2 minutes or until lightly browned. Stir in half the chopped coriander. Tip the potato and lentil mixture into a warmed serving dish and sprinkle with the garlic and cumin seed mixture and the remaining coriander.
Spicy root vegetables and haricot beans: Buy ready-prepared root vegetables such as carrots and parsnips, and omit the potatoes. Cut into bite-sized chunks and cook in salted boiling water for 5 minutes or until barely tender. Drain. Cook the onion and spices, and add the root vegetables as step 3, omitting the lentils, then stir in a 400g can haricot beans, drained and rinsed, and warm through. Add the spinach as before and serve with plain yoghurt.