Heat the oil in a saucepan, add the onion and fry for 5 minutes until lightly browned. Stir in the spices and cook for 1 minute. Mix in the potatoes and drained pulses and stir well.
Add the pickled lemons, stock and seasoning. Bring to the boil then reduce the heat, cover and simmer gently for 40 minutes until the potatoes are tender. Allow to cool, then chill until required.
When ready to serve, reheat the potato mixture on the hob, stirring occasionally and topping up with a little water if needed until piping hot. Spoon into shallow bowls and top with torn coriander leaves and feta cheese, if using. Serve with warmed pitta or flat Arab breads, if liked.