This recipe, courtesy of Anton Edelmann, maitre chef des cuisines at the Savoy in London, serves as the foundation for the Royal Biscuits and Exotic Fruit Tartlets served there for afternoon tea.
By hand, work together 1 pound plus 4 tablespoons of the butter with 1 1/4 cups of the flour on a cool surface. When well mixed, form this butter paste into a block, wrap in plastic wrap, and refrigerate.
Rub the remaining 12 tablespoons butter into the remaining 3 1/2 cups flour with the salt until the mixture resembles fine breadcrumbs. Add 1 cup plus 3 tablespoons water and the lemon juice to form a dough, and mix until smooth and elastic.
Shape the dough into a ball, then cut a cross in the top to one-third of the depth. Open out the points of the cross and roll out each one to a square 5 by 5 inches, 1/4 inch thick. Remove the butter block from refrigerator, and place in the center of the dough. Fold the flaps over, folding counterclockwise and ensuring that the edges are well sealed.
Roll out the dough into a 12-by-24-inch rectangle. Fold the short sides to meet in the middle, then fold in half like a book to form four equal layers; this is called a double turn. Cover with a damp cloth, and chill in the refrigerator for at least 30 minutes.
Repeat to give the dough four more double turns, resting in the refrigerator each time, then leave the dough covered in the refrigerator to rest, preferably overnight before using. The dough can be frozen, tightly wrapped, for future use.