Place a large flameproof casserole or small stockpot over a medium-high heat and add the oil. When it’s hot, add the cumin seeds and let them sizzle for a minute or two. Add the onion with a pinch of salt, stir well, then cover and lower the heat. Let the onion sweat, stirring once or twice, for about 10 minutes.
In the meantime, quarter, deseed and thinly slice the pepper(s). Separate the chard stalks and leaves and cut both into 1cm thick slices. Cut the potatoes into bite-sized chunks.
When the onion is nice and soft, stir in the garlic, then add the red pepper, chard stalks and potatoes. Replace the lid and cook gently for about 20 minutes until the pepper is softened, stirring now and again to ensure nothing sticks and burns.
Add the tomatoes with their juice, crushing them with your hands as you do so. Add the saffron, smoked paprika, sugar and some more salt and pepper and stir well. Simmer gently, uncovered, for about 15 minutes, until the potatoes are tender, stirring regularly.
Toss in the chard leaves, cover the pan and cook for another five minutes, or until they have wilted. Stir the leaves into the stew. Take off the heat.
Add the lemon juice, then taste and adjust seasoning as necessary, with more salt, pepper and/or lemon. Serve scattered with the toasted almonds and coriander and a trickle of extra virgin oil.