Meanwhile, heat the oil in a lidded frying pan over a medium heat. Add the garlic and chard. Stir and season, then add 50ml/2fl oz water.
Place a lid on the pan, turn down the heat and cook for 3–4 minutes, stirring halfway through. Stir in the beans and cumin, cover and cook until the stalks are tender, adding a dash more water if needed.
Meanwhile, to make the dressing, mix together the ingredients with a pinch of salt and set aside.
Split each baked potato in half, top with the beans and chard, a squeeze of lemon juice and drizzle over the dressing.