Creamy Green Lentil Dahl

Heat the oil in a deep, lidded frying pan or casserole dish.
Peel and finely slice the red onion and fry gently for 3-4 minutes.
Add the garlic and ginger, cook for a further minute. De-seed and slice the chilli and add to the pan along with the garam masala, turmeric and chilli flakes.
Rinse the green lentils until the water runs clear, then add to the pan. Add most of the coconut milk, (keep back just a few tablespoons in the bottom of the tin), and vegetable stock. Season generously with salt and black pepper.
Bring to the boil, then reduce to a gentle simmer. Cover with the lid, and cook for 30 minutes, stirring regularly to stop the lentils sticking on the bottom. Remove the lid and cook for a further 15-20 minutes until the lentils are cooked through and the dahl is thick.
Roughly chop the spinach or kale and stir through the dahl for the final minute of cooking time.
Add the juice and zest of the lemon and the remaining coconut milk and stir through the dahl. Taste and adjust seasoning as required, then serve.