To prepare the pie dough:
Either by hand using a mixing bowl or using a stand mixer with the paddle attachment, blend together the flour, salt and butter at low speed, scraping down the sides of the bowl as necessary. Combine the egg, water and lemon juice. Incorporate the liquid with the flour mixture and blend only until it forms a dough. Do not overmix. The dough should be smooth and shiny. Cover the dough and refrigerate a minimum of 2 hours.
When the dough is well rested, roll it out to ¼-inch thickness. Place the dough over the top of a tall 9-inch springform pan and gently set it into the pan. The interior sides and bottom of the pan will need to be covered with a continuous piece of dough. The edge of the dough should slightly overhang the top of the pan (to help reduce shrinking). Place the dough back into the refrigerator and chill for 30 minutes (to help reduce cracking). Meanwhile, preheat the oven to 300 degrees. After chilling the dough, fill it with pie weights or dried beans and bake 15 to 20 minutes. Set aside to cool.
To prepare the quiche filling:
You will first need to blanch the spinach. Bring a small pot of salted water to a boil. Add the spinach. Stir for 10 to 15 seconds and drain. After it is drained, the spinach will need to be plunged into ice water to stop the cooking.
Place the ham and shredded cheese in the baked pie shell. To make the custard, combine the eggs and spinach, and purée in a blender until smooth. Add the milk and cream, and purée to combine. Season with the salt, pepper and nutmeg. Pour the custard over the ham and cheese, and bake at 325 degrees until the custard is cooked, approximately 1 hour and 40 minutes.
Let the quiche rest until it’s cool enough to handle, then cut into slices and serve.
Garnish each plate with marinated heirloom tomatoes and purslane or watercress.