For the dhal base, pick through the toor dhal to remove any stones. Place it in a colander and rinse under cold running water until the water runs clear. Transfer the rinsed lentils to a slow cooker with the boiling water, ginger and salt. Close the slow cooker and place over a medium heat. Cook for about 15 minutes.
When the lentils are soft and falling apart, release the steam from the slow cooker slowly. Most of the water should have been absorbed during cooking, but gently crush the lentils if any small amount remains. Set aside.
For the tadka, place the vegetable oil in a large saucepan over a medium heat. Add the cassia bark or cinnamon stick and the cloves and let them sizzle for 30 seconds. Add the mustard and cumin seeds and shake the pan gently. After about 30 seconds, stir in the curry leaves, cumin, coriander, turmeric and kashmiri chilli/chilli powder.
Pour the cooked toor dhal base into the seasoned oil and mix well. Simmer gently over a medium heat for 2-3 minutes.
To finish, pour in the coconut milk, add the palm sugar or jaggery and kale. Simmer gently for 10 minutes to allow the kale to soften.
Meanwhile, toast the coconut chips in a hot, dry frying pan or skillet for 2-3 minutes, stirring constantly, until crisp and toasted.
Divide the dhal into serving bowls and top each one with toasted coconut chips. Serve on its own or with cooked rice or naan breads. Here, sweet, nutty coconut milk is added to the toor dhal base alongside the spiced seasoned oil. Super-healthy kale and coconut chips bring an extra dimension of texture.