1. Fill and boil your kettle. Peel and thinly slice the garlic cloves. Set half to one side. Halve the chilli and flick out the seeds and white pith for less heat, or leave them in. Thinly slice the chilli. Peel, halve and thinly slice the onions. Peel and grate the ginger. Dice the tomatoes.
2. Put your largest pan on a medium-high heat. When the pan is warm, add 3 tbsp oil. Tip in the black mustard seeds, half the sliced garlic and the thinly sliced chilli. Add a large pinch of salt and fry for 1-2 mins till the garlic is pale golden and crispy, and the mustard seeds begin to pop. Tip this, including the oil into a small bowl. This is the topping for your dal. Set aside.
3. Put the pan back on a medium heat and add 1 more tbsp oil. Add the onions with a pinch of salt. Cook for 5-8 mins, stirring now and then, till the onion is glossy and lightly coloured. Add the remaining garlic and the ginger. Stir for 1 min.
4. Tip in the tomatoes and add the curry powder and the fennel seeds. Cook and stir for 2 mins till the tomatoes are slightly softened and the pan smells aromatic.
5. Tip the lentils into the pan and stir. Pour in 1.25 ltr hot water from the kettle and turn the heat down to low. Pop on a lid and simmer for 10 mins.
6. While the lentils are cooking, trim and coarsely grate the courgettes. Zest the lemon and cut the lemon into 6 wedges. Finely shred the spinach, removing any thick stems.
8. When the lentils have cooked for 10 mins, add the courgettes to the pan. Pour in 500ml more hot water and stir. Cook for 10 mins. Stir once or twice to check the dal isn’t sticking to the bottom of the pan. After 10 mins, the lentils should be thick. Stir the spinach into the dal to wilt it slightly. Taste and season the dal with more salt, if you think it needs it.
9. Ladle the dal into warm bowls and spoon over the fried garlic, mustard seeds and chilli with a little of the spiced oil. Sprinkle over the lemon zest and serve with lemon wedges to squeeze over
10. Eat Me, Keep Me
The dal will keep for up to 3 days in the fridge, or you cna freeze it for up to 3 months. Cool the curry and stir through the fried aromatics and oil. Divide into smaller portions and store in sealed tubs. Defrost overnight, if frozen, and reheat thoroughly before eating.