For the Roasted Sweet Potato, Chickpea and Spinach Curry
Wash and dice the sweet potato, spread out on a baking tray and cover with half the curry powder, a little vegetable oil and salt. Mix well and roast for 15-20 minutes at 180°C/350°F/gas mark 4 until just cooked.
While this is cooking, in a thick bottom pan fry in vegetable oil; roughly chopped onions, 2 garlic cloves, ginger and 1 deseeded green chilli, for approximately 3 to 4 minutes.
Reduce the heat and add the remaining curry powder, half the cumin seeds and half the garam masala. Continuously stir until you can smell the aromas of the spices. Add the tomato purée and stir.
Add the chopped tomatoes and vegetable stock, and simmer gently for 15 minutes. Either transfer to a food processor or use a stick blender to blitz the base curry to a smooth sauce, and return to the pan on a low heat.
Add the sweet potato and chickpeas to the sauce, season to taste. Finish by adding the spinach 5 minutes before serving to retain its colour.
For the Tarka Dhal
Wash the dried lentils (channa dal or split chickpeas) under cold running water until the water runs clear.
Add the lentils to 1 litre of fresh water and bring to the boil, reduce the heat and simmer for 30 minutes until the lentils are just cooked. Strain in a colander and set aside. Throughout cooking, skim any foam residual from the on top of the water.
In a saucepan on medium, heat a little vegetable oil; add 1 minced garlic clove, 1 green chilli scored whole, mustard seeds, turmeric and the remaining cumin seeds and garam masala. Cook for 1-2 minutes making sure it doesn’t catch.
Add 100 ml+ of water to the spice mix and the cooked lentils. Continue cooking the dhal until the lentils begin to break down adding more water to achieve consistency. Season with salt and cracked black pepper, and finish with freshly chopped coriander.
Serve the curry and dhal in a wide bowl and garnish with more fresh coriander.