To prepare the artichokes, first remove the top two layers of the leaves, then cut off the top third of the artichoke. With a small knife or a peeler, peel the artichokes from the bottom of the stalk to the top: you don’t want to be able to see any dark green, just the pale layer underneath.
Put the peeled artichokes into a large bowl of water with the juice of the 2½ lemons and the parsley stalks: these will stop the artichokes discolouring while you prepare the rest. Leave for 20–30 minutes. (Meanwhile, you can prepare the shallots, garlic, parsley leaves and jamón.)
Rinse the artichokes thoroughly. If they are small, cut them in half lengthways; if they are larger, cut them in quarters lengthways. Looking at the size of the stalk is a good guide for judging this: you don’t want to cut it so thin that when you fry the artichokes the stalks disappear.
Heat the olive oil in a large pan on a medium heat and, when it starts to get hot, add the artichokes. Keep them moving constantly and, when they start to turn slightly golden brown, add the garlic. Sweat slightly, then add the shallots and fry for 30 seconds or so. Now add the jamón – turn it with a spoon about four times, then switch off the heat. Add the parsley leaves and lemon thyme, drizzle with more olive oil, season with salt and pepper, then squeeze over the lemon and toss together.