Swiss Chard Curry with potato & lentils

Heat the oil in a large pan (one with a lid), and add the onion. Fry over a gentle heat for 2-3 minutes until starting to soften.
Peel and crush the garlic cloves, and peel and finely chop the ginger. Add them both to the pan and cook for a further minute.
Then add either the spice paste or the turmeric, cumin and chilli flakes. Roughly chop the tomatoes and add them to the pan with all their juices and seeds. Continue to fry gently for a further 3-4 minutes.
Slice the potatoes into thick rounds.
Drain and rinse the tinned lentils and add them to the pan, along with the potatoes and the water, (top tip - you can refill the empty lentil tin half-way with water to save measuring 200ml). Season well with salt and black pepper.
Bring to the boil, then cover with a lid and simmer gently for 15 minutes, or until the potatoes are softened. Stir from time to time, and if the mixture looks a little dry, add a little more water.
Separate the stalks from the leaves of the chard, (set the leaves aside for later).
Trim the ends of the stalks, then slice them diagonally. Add them to the pan.
Tip in the coconut milk and bring back to the boil. Return to a gentle simmer and cook for 5 minutes, (uncovered). Taste and add more salt if required.
Finely chop the chard leaves, then stir these through the curry just two minutes before the end of cooking. Finally, turn off the heat, squeeze the juice of the lemon into the pan and stir through. Serve with rice and naan bread.