Whisk or sift together the flour, 2 tablespoons sugar, and salt. Add the butter and lard and cut it in with a pastry blender until it resembles coarse meal. Add about 1/3 cup of ice water and work it in. Keep adding water by spoonfuls until the dough is just holding together. Gather it into a ball, cover with plastic wrap, and chill 20 minutes.
Note: the pastry can be made in a food processor fitted with a steel blade. Chill the blade 5 minutes, then fit it in the work bowl. Add the flour, sugar, and salt and pulse to sift. Add the fat and process until it resembles coarse meal. Pulse in the water a little at a time, starting with 1/3 cup, until it is holding together. Wrap and chill as in the hand method.
Position a rack in the center of the oven and preheat to 375 degrees F. Line a 12-inch round tart pan with the dough, pressing it into the sides without stretching it. Prick well with a fork, and chill it for 20-30 minutes. Line with buttered foil (buttered side down), fill with pie weights or dried beans, and bake 20 minutes. Carefully remove the foil and weights and bake 8-to-10 minutes more, or until just beginning to color. Sprinkle the bottom with cinnamon sugar and let it cool while preparing the peaches.
Peel the peaches, halve, pit, and slice them into thick wedges. Arrange top of the crust in a single layer, slightly overlapping, in concentric circles. Sprinkle well with cinnamon sugar and a generously grating of nutmeg.
Bake until the peaches are tender and the crust golden brown, about 40 minutes. Melt the jam with the remaining sugar over medium-low heat and simmer 3 to 5 minutes. Let the tart cool slightly and brush it generously with glaze. Serve warm or at room temperature.