Pour the water and lemon slices into a large pan. Break the stem at the base of the artichokes, snap off all the rows of leaves from the head, right up to the artichoke heart. Place the artichokes in the lemon water immediately, bring to the boil, season with salt. Reduce the heat, simmer for approx. 30 mins. Remove, drain, remove the fuzzy centre with a spoon.
Without adding any oil, toast the nuts in an uncoated frying pan until golden brown.
Heat the oil in the same pan, briefly sauté the spring onion, add all of the ingredients up to and including the paprika, cook for a further 5 mins., season. Stir in the nuts, lemon zest, lemon juice, parsley and half of the cheese. Stuff the artichokes with the mixture, transfer to the prepared dish, sprinkle with the remainder of the cheese.
Approx. 10 mins. in the upper half of an oven preheated to 220°C.