To make the pastry, stir together the flour and salt in a bowl. Cut in the butter with knives or a pastry blender until the mixture resembles coarse meal. Blend in the egg and as much water as needed for the dough to come together into a rough ball. Flatten into a disk, place in a plastic bag, and refrigerate 1 hour. Select a
On a lightly floured board, roll out the pastry into a
While the pastry is chilling, prepare the filling: Have ready a large bowl of water to which you have added the lemon juice. Working with 1 artichoke at a time, remove the stem and all the leaves until you reach the pale green heart. Peel away the dark green area from the base. Drop into the lemon water. Bring a saucepan of water to a boil. Drain the artichokes, add to the boiling water, and cook until just tender, about 15 minutes. Drain and, when cool enough to handle, cut in half lengthwise and scoop out and discard the chokes. Slice the halves lengthwise.
Arrange the artichokes in the pastry shell. Top with the slices of hard-boiled egg. Sprinkle with salt and pepper and a generous grating of nutmeg. In a bowl, whisk together